Making Strides Toward Low-Cost LED Lighting

Roland Piquepaille writes "You all know that incandescent bulbs are pretty inefficient, converting only 10% of electricity into light — and 90% into heat. Light-emitting diodes, or LEDs, could soon replace incandescent and compact fluorescent bulbs in our homes. They are more efficient and environmentally friendly. But LED lights are currently too expensive because they are using a sapphire-based technology. Now, Purdue University researchers have found a way to build low-cost and bright LEDs for home lighting. According to the researchers, the LED lights now on the market cost about $100 while LED lights based on their new technology could be commercially available within a couple of years for a cost of about $5. It would also help to cut our electricity bill by about 10%."

Comments

Yea,

[jsmiith]

But how much of an improvement will they be over fluorescent lights, which we already have at an affordable price?

Re:Yea,

[Anonymous Coward]

They will be way more environmentally friendly. No mercury involved.

Re:Yea,

[NFN_NLN]

But how much of an improvement will they be over fluorescent lights, which we already have at an affordable price?

Less mercury.

Re:Yea,

[nhtshot]

No mercury = huge improvement

Re:Yea,

[pushing-robot]

But how much of an improvement will they be over fluorescent lights, which we already have at an affordable price?

Well, they won't flicker, they won't contain mercury, and they won't be too big to fit in many light fixtures.

Even if LEDs aren't any more efficient than current CFLs, they'll be a lot more attractive to people who don't like or can't use fluorescent lights.

Re:Yea,

[A nonymous Coward]

In addition the no mercuary as already noted, they will have a longer life, be less fragile, and be smaller.

Re:Yea,

[Anonymous Coward]

1> They last longer
2> They cost less to use

Add up the savings through these two points and the inevitable conclusion must be that some researchers at Purdue University (or the people financing them) look set to make a fortune.

Re:Yea,

[Anonymous Coward]

Let's not forget improved cold weather characteristics

Re:Yea,

[sdpuppy]

Also, TFA states that LEDs have the potential to well surpass fluorescent bulbs in terms of energy efficiency.

Another article http://pubs.acs.org/isubscribe/journals/cen/86/i28/html/8628cover4.html provides some interesting information on organic LEDs - OLEDs have interesting design applications since you can make them in flat sheets

(I think an illuminating wall would be way cool, but maybe thats just me :-))

Right now efficiencies are similar to the inorganic LEDs and fluorescent bulbs.

Re:Yea,

[tomhudson]

Poster saith:

Let's not forget improved cold weather characteristics

TFA saith:

"You all know that incandescent bulbs are pretty inefficient, converting only 10% of electricity into light and 90% into heat

Me: "I live in Canuckistanbul - we NEED the heat, you ignorant clods!"

Electricity costs less than oil or gas here ... it's cheaper to get some extra BTUs from incandescents in the winter months ...

Re:Yea,

[SeaFox]

Well, they won't flicker, they won't contain mercury, and they won't be too big to fit in many light fixtures.

2003 called, it wants it's CFL stereotypes back.

CFLs don't flicker like old ballast-type fluorescent tubes of decades ago. And the newer ultra-compact ones are actually smaller than the incandescent bulbs they replace. I have one in the swing-arm desk lamp in front of me right now, and the tip of the bulb no longer protrudes past the end of the shade like the old bulbs I used in it long ago. In my bathroom I have CFL bulbs made to look identical to G25 globe lights, in the same fixture with the actual incandescent bulb I am slowly replacing. They appear the same except the CFLs are brighter and their light isn't as yellow.

I will give you the mercury, though.

Re:Yea,

[Anonymous Coward]

But how much of an improvement will they be over fluorescent lights, which we already have at an affordable price?

The efficiency of Fluorescent lamps is about 22% (compared with 10% of incandescents.) LEDs are over twice as efficient as Fluorescent bulbs. They also last much, much longer.

I have a few LED led bulbs installed around my apartment (equivalent to a 30 watt bulb) and they are too "cool" for me to consider using them as my only lighting. The sun produces 100% on the "Color Rendering Index" scale. Incandescents produce about 80% CRI. LEDs are still only at about 70% CRI.

Re:Yea,

[funaho]

They'll also have a longer lifetime than CFLs. The article says they could last as long as 15 years, compared to CFLs which I believe have an expected life of about 7 years.

Re:Yea,

[kaizokuace]

not just an illuminating wall. Imagine the entire ceiling covered in an OLED sheet and have lighting do cool stuff like follow you around or whatever. Rooms with people get lit while others don't. Crazy flashy lights for parties. the possibilities are limitless!

Re:Yea,

[A beautiful mind]

The mercury depends on efficiency aswell. Modern CFLs have <=2mg mercury content, (at least the CFLs I own). Over a 5 year period, the electricity needed for CFLs, generated by coal based power plants in some portion, releases 2.4mg of mercury into the air. For incandescents the number is 10mg over a 5 year period. LED lighting is currently less efficient than CFL, so more mercury gets into the air.

The question is really, whether you prefer 2.4mg of mercury in air plus 2mg in the landfills, or more than 2.4mg of mercury in the air. Until LEDs become more efficient than CFLs, I'll opt for CFLs.

Note, there is a confusion over LED vs CFL efficiency. LEDs generate light more efficiently than CFLs, but they do so in a narrow arc. To make it useful for everday applications conversion to a wider arc takes place and that causes efficiency loss.

Re:Yea,

[Hatta]

No, they don't flicker any more but they still look like crap. I'm sitting under one right now, and it wouldn't be tolerable if I didn't have an incandescent right next to it. I prefer the warm yellow tinge of incandescents to the cold blue hue of CFLs.

Re:Yea,

[parens]

If I might inquire - where do you find these smaller CFLs ? Every CF i've seen retail for years now has been some crappy generic brand with a giant ballast and protruding bulb tips, not to mention they still burn out just as often as incandescents. I'd love to switch my home over to CFLs, but every time i've tried to, I either have size problems, color temperature problems, audible buzzing, and/or burnouts.

Re:Yea,

[wooferhound]

The article says that the LED lighting is equaling the efficiency of Fluorescent lighting, But if you look around for LED Efficiency you will find that LED lights are very much less efficient than Florescent lights. I believe they were more talking about a cheaper way to make LED lighting, but it's not any more efficient.

Re:Yea,

[Translation Error]

I will give you the mercury, though.

No, thank you.

Re:Yea,

[Aaron B Lingwood]

>2003 called, it wants it's CFL stereotypes back.

>CFLs don't flicker...

CFLs cause me migraines and other visual problems. I recently changed all my home lighting, where possible, to CFLs.

After a week, I began suffering from an extreme migraine. As the CFL's made it difficult for me to read or focus on small objects - I instantly held them suspect. To test my theory, I changed all the lighting back, and by the next day my life had certainly improved.

I gave it a month and tried the CFL's again, and again after a week a migraine set in. I intend to remove them tomorrow. My girlfriend (as in a living 3D female human-being) who doesn't normally suffer from migraines has been complaining of symptoms while I had the CFLs in.

I think CFLs definitely have a use but not as a be all and end all of general home lighting. The most pleasant affordable technology for me is halogen lighting. I am looking forward to what LED and OLED technology has to offer in the near future.

--
Deceive the rich and powerful if you will, but don't insult them.

Re:Yea,

[zOper]

I prefer heating my rooms with computers and plasma/LCD panels. ;)

Re:Yea,

[pz]

Well, they won't flicker, they won't contain mercury, and they won't be too big to fit in many light fixtures.

Even if LEDs aren't any more efficient than current CFLs, they'll be a lot more attractive to people who don't like or can't use fluorescent lights.

Have you actually looked at high-quality CFL bulbs? A good daylight bulb is a thing of beauty. No flicker (and, you know, CFL bulbs have never had flicker because they are run at much, much higher frequencies than you visual sytem can see), proper color balance, small, reliable, quiet.

Note that I'm not talking about the two or four foot long fluorescent bulbs that you might have in your office. Those are probably not daylight balanced and probably flicker at 120 Hz (yes, 120 Hz, not 60 Hz, because both half cycles push current; unless you're in part of the world which runs on 50 Hz mains, in which case they flicker at 100 Hz). Their ballasts also have a tendency to buzz.

Good CFLs are wonderful.

Note, also, that many LED bulbs you can get these days are simply awful because they flicker at 60 Hz (yes, 60 Hz, because they're arranged in cascading diode fashion and only conduct on every other half cycle) and the phosphors are terrible. They also lose brightness at an astonishing rate and are horribly temperature sensitive (hotter chip, lower light output). The 60 Hz issue can certainly be fixed with better circuitry (ie, bridge rectifiers and some low-pass filtering) and one hopes that the phosphors and lifetime improve.

Wait, phosphors in an LED? What am I smoking? Yes, it's true, most white LED bulbs for sale are actually UV emitters that excite phosphors. And just like fluorescents, the better the phosphors, the better the output spectrum. While it is possible to generate white-ish light from a combination of red, blue, and green LEDs, because the aging curves are different for the three classes of emitters, the color balance is dynamic over the bulb lifetime. And, also, the spectrum is terrible -- even the spectrum from fluorescents is better -- because it's essentially three isolated wavelengths instead of a continuous spectrum.

LEDs have a long, long way to go before they can be used in living or working spaces.

Re:Yea,

[matt_martin]

> But how much of an improvement will they be over fluorescent lights, which we already have at an affordable price?

They are "all solid state" and should not have any of the start-up issues that CFL's have, which will hopefully help both usability AND reliability.
And if you've used CFL's on any scale, you'll certainly know that the quality/reliability of these products is miserable bordering on pathetic. I'm currently quite convinced that my switch to CFLs has cost more energy (and money) in terms of replacing failing bulbs than it has saved in electricity. The performance is so poor that I've gone to writing the date on the base an saving every receipt and package.

Re:Yea,

[Rutulian]

I get mine from IKEA, although I'm sure there's a better place. Costco, BJ's, Home Depot...CFLs are everywhere. Where have you been looking?

I've never had a CFL burnout, flicker, or buzz. They do have whiter light, but I prefer that myself.

Re:Yea,

[Anonymous Coward]

You know there is such a thing as electric panel ovens. Being from another cold country with cheap electricity (Norway), I actually made it to 25 without ever living anywhere with central heating - we had electric panel ovens in every room. Central heating was something I grew up with considering as something old and obsolete you'd find in worn down school buildings.

Re:Yea,

[hedwards]

Fluorescent lighting is just horrible. It has been made to suck less over the years, but it's still expensive to get the good lights. The ones that don't suck the life out of a person as described at the beginning of Joe versus the volcano.

LEDs aren't as bad, but they're quite bright and I personally cringe when people suggest that the alternatives to incandescent light bulbs are truly ready for prime time.

As somebody who suffered severe eye aches during the period when people were still using halogen lights, energy draining migraines from fluorescent lights. I really have to wonder if the scientists that are developing these technologies are thinking at all about my best interest rather than what cool toys they can get deployed.

Honestly, I'm all for technological advances, but they have to be thought out ahead of time. I'm not willing to put up with the kind of maddening side effects that I have been over the years because somebody thinks that I'm wasting power.

I shouldn't have to avoid certain public areas because the monitors are throwing my tinnitus into overdrive or avoid others because the lighting is giving me the kind of eye aches that hurt more than forcibly removing the eyes.

Re:Yea,

[SeaFox]

I bought mine at Wal-Mart. They're GE brand and were right next to their older, longer GE bretheren on the display. The package said "Smaller Size" right on it in big letters. They came in a two pack instead of a three, and they are more expensive than the older ones. But they also put out a few lumens more (not much, but still slightly higher) than the longer ones, even though they were both rated for the same "incandescent watt" equivalent. They are rated for longer life though, 10,000 hours verses 8,000 for the older ones.

I just attempted to measure, and the bulb is almost an entire inch back from the edge of the lamp shade (this is with a 60w equiv. bulb).

GE only offers two color temperatures in its bulbs (faux incandescent color, and cool blue). Home Depot sells a brand called n:vision that comes in three temperatures. They also seem to be ultra-compact, but not quite as small as the GEs, they are cheaper though. I picked up these to replace the CFLs in my ceiling fixture when I moved into my place (I found the ones already there too yellow). I couldn't fit the old bulbs into the package for storage easily because they were longer than the n:visions brand.

The G25 bulbs were also GE brand, but I can only find them at Target and Ace Hardware, Wal-Mart sells a Philips brand I tried that is really lousy (like three bulbs have burnt out in one year bad, the old incandescent beat them in life). The GE G25 CFL bulbs are slightly smaller in globe diameter than the incandescent, but it's not that noticeable. They are also rated at 10,000 hrs.

Re:Yea,

[dvice_null]

I got one LED bulb currently on providing me the light for computer usage. It is a spot light and consumes only 2,5W of energy, compared to 12W which my previous energy-saver bulb consumed and 60W which the first "normal" bulb consumed.

It provides enough light for me and saves a lot of electricity compared to the alternatives. It also looks very cool, because of its small size. But the long life (which I assume they have) is the real reason why I prefer them.)

Re:Yea,

[jacquesm]

I have a new way to deal with Roland Piquepaille spam, every time I see an article by him I go away for 3 days.

So, see you on the 24th...

Re:Yea,

[Damarkus13]

Yeah, my mother had the same problem. She replaced every bulb in the house with CFLs and within 12 hours had a incapacitating migraine. Granted, she has a history of migraines and flourencent lighting is one of her triggers, but she was told "The new CFLs don't flicker anymore!" by a helpful sales person at her local big box store.

So the grandparent post must mean they don't visibly flicker, just like a CRT when you crank the refresh up to 120Hz. Unless he would care to cite a source proving they don't flicker at all.

Re:Yea,

[xaxa]

I've never had a CFL burnout

They will do. My parents were early adopters (must be over 15 years since we had them), I think the only incandescent light in their house is in the microwave.

I remember the first ones cost about £10 and were massive, heavy things and they did flicker, and take five minutes to warm up. But the ones made in the last 5 years or more are brighter, white, don't flicker, and don't buzz. They do (eventually) burn out though.

Yellowy incandescent lights remind me of my grandma's house; admittedly the yellow effect was enhanced by her cigarette smoke.

Re:Yea,

[xaxa]

Did you buy $1 bulbs? If so, you should spend a bit more than that.

(The only time in the last five years that I've had a flickery bulb was when I spent £0.99 on the no-brand bulb as they'd sold out of "proper" ones, and that includes buying CFLs for all the fittings in three rented properties that I forgot to take with me when I moved out.)

Re:Yea,

[EvilBudMan]

They are already more efficient. I have a 3W MagLite that runs on 2AA and will blind you.

Mercury in the CFL's are not as much of a concern as mercury in those 4' flouro's of the commercial buildings, but maybe they are more likely to be recycled.

Eating tuna might be more of a problem though.
http://www.gotmercury.org/article.php?list=type&type=75

Re:Yea,

[Aaron B Lingwood]

I purchased a few different types.

Ranging in price from $6.99 each to $24.99 ea.

--
All prices quoted in Australian Dollars.

Re:Yea,

[QuasiEvil]

How do you figure they won't flicker? Incoming power is still 60Hz, and to fix that they'd need to incorporate a rather large capacitor, which would in turn foul up the power factor, etc...

Re:Yea,

[yayotters]

A ceiling covered by an OLED sheet...
Now that'd be really awesome...

Or depending on how small the OLED's can be made, you could create a star/night time sky scene.

Re:Yea,

[kesuki]

"Well, they won't flicker"

I beg to differ, without a full wave rectifier, or DC converter, LEDs Will flicker, specifically,

"For an imaginary cycle of 360 degrees of the AC line, about 26.5deg (1.2msec) pass before the line gets to 75V and the LEDs start to emit light. Then the LEDs are on for 127deg (5.9msec), and off for the remaining 206.5deg (9.6msec). That means we get a 5.9msec hump or pulse of light every 16.7msec: The LEDs are actually ON only about 35 percent of the time "

not good, although a full wave rectifier can be built for less than $5 worth of parts at radioshack.. oh hey, and some bulbs actually take advantage of being able to make LEDs switch on and off quickly to emulate dimmer functionality.

you can't put fluorescent lighting on a dimmer, albeit, LED dimmers are a bit more sophisticated than 'dumb' dimmer knobs, at least it's possible.

Re:Yea,

[Orange Crush]

While CFLs (and fluorescents in general) have improved greatly recently, there are still a few drawbacks vs incandescents. LEDs would fix some of these, but not all:

-They're not full spectrum like sunlight and incandescents. Each phosphor emits light in a fairly narrow spectrum, but by using three or four colors in the coating mix, warm white and daylight can be approximated, but it still ends up looking a little "weird" to me. LEDs have the same problem, unfortunately.
-While the overall mercury impact is lower in CFLs over their lifetimes, you still have a lot of fairly fragile glass tubes with mercury vapor in your house.
-All of today's CFLs are NOT created equally. Quality of manufacture has a huge impact on the quality of the light you get. You often need to try several different brands before you find a good one. LEDs will likely have this same problem too.
-Fluorescents only last long if they aren't power cycled often, otherwise they can die faster than a comparable incandescent.

I use CFLs throughout the house for most purposes, with incandescents in the bathrooms, closets and motion sensor driveway light due to frequent power cycles. I also keep incandescents in the kitchen for the full spectrum light which I feel makes a difference in the appearance of food when I cook.

Re:Yea,

[PhoenixFlare]

Got mine at Target, GE brand. Every light in our place (aside from the big regular-fluorescent tube fixture in the kitchen) is a CFL...They fit everywhere (even the 20-year old fixtures in the hallway and dining room), no sound at all, no burnouts in about 1.5 years so far.

Color temperature is a bit cold, but not overly so, and oddly, seems to blend with the sunlight very well.

Re:Yea,

[kesuki]

'Me: "I live in Canuckistanbul - we NEED the heat, you ignorant clods!" '

um, that heat really does you a lot of good up there on the ceiling, that 60 watt desk lamp is probably too far away from you as well.

just pointing out that thermodynamics mean that all that waste heat is really wasted, unless you want to sit directly above your light source, you're getting 0 benefit.

besides, there are plenty of efficient electric heat sources that let you heat just one room, or 'just one person' not to mention you could just wear a parka all the time.

electric blankets don't cost much, and are nice and cozy even from the couch. although in practical terms, you need to keep the pipes from freezing etc, you can keep a place nice and cold, without risking bursting pipes.

Re:Yea,

[pushing-robot]

I've got two of the "high quality" CFLs over my head as we speak. They have 95+ CRI and give everything in the room a very accurate color cast. But if it wasn't for a couple incandescent bulbs next to them I'd have vertigo and a throbbing headache.

It's funny, as I'm not normally the sensitive sort — strobe lights and flashing video games don't bother me in the least, I love bright sunlight, and I'm virtually immune to motion sickness. But stick a CFL in the room (without an equal amount of non-fluorescent light) and I'll be curled up in a corner clutching my head inside of two hours.

And I'm not the only one.

Re:Yea,

[ivan256]

Intensity and light output are two different things. LED lighting doesn't exceed the efficiency of fluorescent lighting in terms of lumens per watt yet. Many LED manufacturers continue to announce products they claim exceed the efficiency of fluorescent lighting, but they haven't actually managed to do it yet. That said, they're getting very close.

Re:Yea,

[Salgak1]

Problem is, drop an LED lamp, and the worst you have to do sweep it up and throw it away. Drop and break a CFL, and you have a hazmat situation. . . Ever read the EPA guidelines on cleaning up broken CFLs ??? ??? Illuminating, indeed. . .

Re:Yea,

[tomhudson]

The "waste heat" that goes to the ceiling would go to the ceiling anyway, if it were from a baseboard heater. Also, the heat does cause convection currents - as does the heat and air circulation from the main heating system. You won't find as much temperature stratification as you would think at first blush.

electric blankets don't cost much, and are nice and cozy even from the couch.

Big dogs are better. They work even during a power failure.

Re:Yea,

[QuantumRiff]

I have the globe lights in my bathroom too.. Some people complain about the fact they take a few seconds to get to full brightness, but when I smack the alarm for the 4th time, stumble into the bathroom to take a shower cause I'm running late, I'm damn happy that they take a minute to warm up. I used to hate flicking on those lights when I was half asleep, it was a rude awakening.. (literally)

Re:Yea,

[kesuki]

big dogs are old school, what's the saying "it's a three dog night"

true, they work in a power failure, but have you seen the price of dog food these days? i've never had the power fail on me in winter, and i'm 30 years old. Sure i've heard of it happening, but when you've never experienced something you don't think you ever will.

Re:Yea,

[osgeek]

A CFL that I bought from Ikea 3 years ago flickers horribly some days. Should I send it to you for debugging?

Re:Yea,

[Z00L00K]

The price doesn't really matter, it is if they are HF (high frequency) or LF (low frequency) that matters.

The LF version flickers with 50 or 60 Hz (depending on where you live) while the HF version has a lot higher frequency and will be almost flicker-free.

LED:s also suffers from flickering if you feed them with AC, but if you use DC and a low-pass filter you will get rid of the flickering.

The color spectrum is also different depending on the type of light source.

Re:Yea,

[kklein]

Mine are brand new, major-brand (Toshiba, Panasonic), and they are dim as hell when I turn them on. Whenever these things come up on Slashdot, tons of people talk about how "CFLs don't [insert complaint here] anymore." But I have begun suspecting that they do, but some people just don't notice or care.

It's like people talking about how quiet Macs are. I can hear mine, which means it's not quiet. I couldn't hear the silent PC I built. I am totally open to the idea that I'm just being picky, but for me, CFLs just plain do not satisfy.

I've also seen no drop in my electricity bill.

The only thing I'll give them is that they are a lot cooler (temperature) than incandescents, so I've taken to installing them in the summer, and switching to incandescents in the winter. I can put up with their inherent suckitude for about 4 months of the year, and that's it.

Re:Yea,

[Firehed]

You usually pay EXTRA to get the daylight (bluish compared to incandescent) CF bulbs. I don't understand where this stereotype continues to come for as the most widely available CF bulbs all have an incandescent-like, extremely warm color temperature.

Re:Yea,

[walt-sjc]

And while dimmable CFL's are available at 4-10 times the cost of the non-dimmable ones, they are generally NOT available in most retail outlets such as Lowes, Home Depot, Walmart, Target, your local grocery store, etc. In fact, I can only find them at specialty lighting stores (meaning 8x normal retail price) and mailorder. Since 90% of my lighting is on dimming circuits, this is a major problem for me.

I also wanted to use CFL's in an outdoor security floodlight application, but with the 7 foot diameter base, they don't fit in my fixture. I wanted to use them in a few other places, but they don't fit with the huge bases or extra length. The bulbs available to me all have cold weather problems, and slow startups (taking as much as a minute to get to full brightness for some of them) - I've tried all the brands available to me locally.

I looked for a light sensor to automatically turn on lights at dusk, and every single one specifically said not to use them with CFL's.

I want to use CFL's. I really really do, and I use them where I can (such as the bathrooms.) BUT, I can't use them in many cases where it makes the most sense to use them. You may be fortunate - your local stores may carry the modern bulbs. Mine do not as of this afternoon when I was shopping.

Maybe it's because I don't have an A class Home Depot, or the 700 acre super Walmart isn't quite super enough, but I KNOW I am not alone in my frustration.

I'm very happy you found a bulb that works for you. I have not been so fortunate.

Re:Yea,

[ross.w]

Plus you can use them with a dimmer, and you c

Re:Yea,

[maraist]

* no flicker
* INSTANT on
* INSTANT max-brigtness
* 5W v.s. 16W for a 700lumen bulb replacement LED v.s. CFL - efficiencies scale better for LED than CFL for lower lumans, but benefit CFL for higher lumans.
* lighter
* more durable
* no mercury
* longer life expectancy

The two negatives are the color spectrum and price of LEDs. You can get very nice ranges of colors in CFL's these days (soft, white, 'natural daylight'). The few LED lights I've sampled have very distinct colors.

CFL's are already cheaper than incandecents even if you ignore energy costs (due to 1/4 to 1/10th the replacement schedule). LEDs advertise 6x the life of CFLs. While I'm aware of CFL's not all being equal - cheaper brands get 70% of their advertised life, while many name-brands get 120% of their ratings. LEDs haven't had anywhere near the public testing (because there aren't enough volume vendors to test against).

Re:Yea,

[Anonymous Coward]

I am not going to be burdened with tying
myself to a bunch of radical arabs so
we can continue to buy prehistoric sludge
just to appease your medical issues.

Nor will I allow you to continue pushing
around your ignorant hate campaign and
falsehoods about CFLs to others, slowing
down the transition to CFLs.
[ http://www.google.com/search?q=cfl+misconceptions ]

So, please shut the F* up sir and do
like everyone else and see a DR if you
are having problems. Or complain to your
parents for putting you together incorrectly.

Re:Yea,

[ross.w]

You won't see a drop in you electricity bill with CFLs in the winter if you rely on electric heating. Yes, Incandescent bulbs are only 10% efficient, but where do you think the other 90% goes? If that heat is not being produced by the light, it's being produced by then fan heater instead. Of course almost any other kind of heating is cheaper than direct electric.

Re:Yea,

[macbeth66]

Even if LEDs aren't any more efficient than current CFLs, they'll be a lot more attractive to people who don't like or can't use fluorescent lights.

These guys are doing some very cool things with LEDs; Color Kinetics

Re:Yea,

[RobertM1968]

I have a feeling, that unless this new technology makes grossly inefficient use of power compared to "regular" LEDs, then the 10% figure is based off comparison to flourescents.

That statement is based off the power requirements of current LED lighting offerings compared to CFLs of the same "apparent wattage"

Unfortunately, I couldnt find anything in the article that indicated whether the new technique was more or less efficient - or the same - as the available LED offerings. Without knowing that, it's just speculation.

Of course, there are other advantages, such as the long life. As it is, more and more businesses are looking into LED lighting for just that reason... install once, virtually never replace. They are also ideal in situations where bulbs are hard (and thus costly) to replace like high overhead fixtures.

Re:Yea,

[budgenator]

Electricity use is the main source of mercury emissions in the U.S. CFLs use less electricity than incandescent
lights, meaning CFLs reduce the amount of mercury into the environment. As shown in the table below, a 13-watt,
8,000-rated-hour-life CFL (60-watt equivalent; a common light bulb type) will save 376 kWh over its lifetime, thus
avoiding 4.5 mg of mercury. If the bulb goes to a landfill, overall emissions savings would drop a little, to 4.2 mg. Frequently Asked Questions Information on Compact Fluorescent Light Bulbs (CFLs) and Mercury

That's all well and good but you would be surprised at how much mercury gets into the environment from dental fillings and how few people will pay the extra $15.00 to get composite fillings!

Re:Yea,

[Jorophose]

OLEDs are incredible.

If it wasn't for the fact that they, like anything organic, die, they would be THE material for displays. Already Sony is trying to make TVs out of them, and when the technology is perfected every laptop is going to carry one standard. Get ready for 10+ hour battery life on devices like the Asus eeePC. (For the curious, OLEDs have a life of something like 4500 hours for blue, the shortest lifespan, compared to 500,000 for LEDs. So expect some time before you see everything converted to OLED... It's not impossible; Sony is already doing OLED TVs, but yeah they're pricey, like 2500$ for 11")

Oh, and did I mention, (synthetic?) LEDs don't die. They don't die from on/off usage. They don't die from overuse, at least not in your lifetime (at least, I don't think so). They don't die from being abused. They will only die from a surge, realistically (by that I mean extra volts).

Re:Yea,

[couchslug]

They will use so much less power that it will be easy for people like me to power them with backup power systems when transmission lines are taken down by storms or drunk drivers. I will be able to light my workshop and outbuildings with waterproof potted LEDs instead of high-maintenance bulbs.

Re:Yea,

[budgenator]

I bought some expensive name brand reflectorized CFL bulbs to go into the ceiling fan we installed in the kitchen, and they have startup issues and the 27 watt CFL's outside start slow in mid-winter, but other than that I have had no problem with moderately priced store-brand CFLs. These bulbs seem to be very much a YMMV thing. Sooner or later the problems will be resolved, perhaps due to the hypersensitive being rendered incapable of reproducing under CFL light.

Re:Yea,

[SeaFox]

Mine are brand new, major-brand (Toshiba, Panasonic), and they are dim as hell when I turn them on. Whenever these things come up on Slashdot, tons of people talk about how "CFLs don't [insert complaint here] anymore." But I have begun suspecting that they do, but some people just don't notice or care.

Try a different brand. I had some globe style CFLs by Philips, and they were horrible. Long warm up and the incandescents I had been meaning to replace still outlived them. Tried the same product by GE, made a world of difference.

Re:Yea,

[Chrontius]

Remember the famously short lifetime of OLEDs.

Re:Yea,

[pushing-robot]

Your quote came from an article about cheap LED holiday light strings which run straight 120v AC through 30 or more LEDs in series. LED interior lights (and even better quality holiday strings) are designed differently, using full-wave rectifiers + capacitors or regulated power supplies.

In fact, any LED lighting manufacturer would be shooting themselves in the foot by running LEDs on unrectified AC; the LEDs will put out much less than their optimal radiant flux (because they're only "on" 1/3 of the time) and burn out quickly (from high peak forward and reverse voltages).

Re:Yea,

[mariushm]

And how freaking often do you break a CFL ?

I think it's over 5 years since my parents and myself use only CFL and none broke. What are you doing, jumping on beds and hitting the lights with your head?

From about 20 lamps I bought, about 4 wouldn't start after being turned off, none broke. From those 4, I was able to resurrect two by doing some soldering inside them (cheap capacitors and coils inside on some 3-4 years old models)

Seriously, the mercury inside a CFL lamp is anyway probably less than the mercury contained in 5-6 cans on tuna fish so stop with the stupidity.

Re:Yea,

[Secrity]

For applications such as refrigerator lights, the warm up delay of a CFL is unacceptable (if it will even start). The LEDs in my refrigerator also look cool.

Re:Yea,

[pjbgravely]

um, that heat really does you a lot of good up there on the ceiling, that 60 watt desk lamp is probably too far away from you as well.

Um no, incandescent lamps also produce infrared heat which travels in a straight line and heats objects. They work great horizontally from an object you want to heat. No need to have it under it.

Re:Yea,

[tomhudson]

We had an ice storm a decade ago - no power for a month. The room with my Newfie was warmer than any other room, and he certainly kept me warm at night ...

Re:Yea,

[Guppy]

The mercury depends on efficiency aswell. Modern CFLs have

To put that into perspective, 5 pounds of your average Swordfish would have more mercury than a modern CFL -- and you don't eat the bits of a broken CFL.

Re:Yea,

[Your Pal Dave]

Plus you can use them with a dimmer, and you c

...andle Jack?

Re:Yea,

[blitziod]

4500 hours? that sonly 187 days? So the new OLED tv lasts 6 months? at 2500 bucks a unit that is a deal that needs lots of LUBE!

Re:Yea,

[blitziod]

i have those annoying globe style vanity lites in my bathroom. It is a rental so i can not change it. Over 2 years i have replaced SOOO many of them, and they cost a bundle. This last time i tried CFL's. 6 months and no replacement. They cost about twice as much, so I am already ahead of the game. They do take a second to warm up though...but this does not bother me esp in the bath.

Re:Yea,

[blitziod]

i had the pwer out for almost a day in a snow storm in dallas texas of all places...I did not however have a dog...luckily I had blankets and a girlfriend!

Re:Yea,

[fluffman86]

One night, I had to replace a light bulb in the bathroom over the sink. It was a pretty far reach but I was able to remove the old incandescent fine. I had one more CFL in an open pack of bulbs. As I was trying to screw it in, I dropped it in the sink and it shattered.

Crap. Well, that's OK...I don't really use that CFL in the ceiling much, and since I use the light over the sink more I'll just pull the CFL from the ceiling and put a spare incandescent there. Unscrew, unscrew....*CRASH*

So to answer your question...twice in one night :P

Re:Yea,

[jagdish]

You could vote it down in the firehose.

Re:Yea,

[eyrieowl]

sounds like the perfect lighting material if you're a manufacturer...a nice guarantee that your customer will come back over and over and over....

Re:Yea,

[Anonymous Coward]

I hope your girlfriend receives a slashdotting worth of friend requests because of that link

Re:Yea,

[Anonymous Coward]

Maybe some day the US will get the idea that you shouldn't put things containing mercury (and other things toxic to our planet) into household waste that will end up in landfills. Here in Europe we actually recycle (!) and CFL bulbs do not go into landfills, they are properly recycled so the mercury doesn't end up where it shouldn't be. My entire house is lit using only CFL bulbs and I'm not concerned with the mercury. When a CFL bulb needs replacement after many years of service, the old one does not go into household waste.

A bit OT, but many waste "problems" are solved by proper recycling. This also includes discarded electronic equipment like old PC's, monitors and household appliances.

Re:Yea,

[jonbryce]

I guess they switch on immediately, rather than taking a few minutes to warm up. Some CFLs are quicker than other at warming up though.

Re:Yea,

[LordVader717]

Plus they can be dimmed, unlike CFLs. And they don't produce a mor yellow light while doing so, like incendecent bulbs.

Re:Yea,

[LordVader717]

There probably isn't enough energy saved to make a very noticable drop in the electricity bill anway, especially if you only use them 4 months a year. General fluctuations will probably be more pronounced.
And it's unreasonable to expect a Mac to be quiter than a specifically custom-built silent PC. What is true though is that they typically produce less noise than comparable offerings by other major PC brands.

Re:Yea,

[zwarte piet]

Finally someone with some sense. In cold climates using incandescent bulbs indoors isn't inefficient. It's just efficient bright heating!!

Re:Yea,

[Ullteppe]

Completely agree. I have started to realize that I am more sensitive to flicker than the average, I absolutely loved going from CRT to LCD as my viewing comfort went way up.

I have also definitely seen flicker in both CFLs and regular fluorescent tubes (which, BTW, is still the dominating light fixture in commercial buildings). I'm not saying all of them are bad, I'm sitting in a room lit by a CFL right now, and have no issues with that bulb.

I have a more long-term philosophical argument for LEDs to win to - lighting is the only remaining area where vacuum-state technology is still dominant. Semiconductors killed vacuum tubes outside of niche applications a long time ago, LCDs have killed CRT over the last 10 years (and this happened quicker than even the most optimistic LCD proponents predicted), now the only battlefield left is LED vs. Edison's bulb (looks to become extinct very soon, IMHO) and CFL/regular fluorescent lighting.

Sure LEDs still have some issues, but these are minor compared to those that have been overcome over the last 10 years or so (color, intensity). LEDs gain all the economic advantages of wafer-type manufacturing, and just like we saw with LCD, I am confident the price is going to go WAY down compared to today.

Besides, LEDs have the potential to enable things that are just not possible with vacuum-state lighting - sealed lamps because you don't need to change bulbs (once lifetime is improved), completely different form factors as well as colored light. Once this becomes fashion (the LED headlights on Audi cars are already becoming a fashion statement), the LED market will explode.

Re:Yea,

[Cpt. Fwiffo]

Funny thing, that.
The dutch wikipedia site shows they do:
Dutch article on Ledlamps
See the table...

Re:Yea,

[Wavebreak]

Where, then, are you proposing the heat actually goes? Basic thermodynamics, energy does not simply disappear. Some minor fraction might escape via various means, but the rest eventually ends up in the air of the room, and convection takes care of the rest. It might not be *fast*, but that doesn't mean it's wasted. Also, it's physically impossible to have an inefficient heat source, so I'm not seeing the point of describing one as efficient. Effective, sure. Efficient, no. It's certainly possible to use less energy by heating only what is necessary (i.e. yourself), but that's a matter of targeted heat transfer, not efficiency. If, on the other hand, you want to keep a room or a house warm, the only relevant factor is the rate of heat transfer from within the system to the surroundings - any transfer of heat into the system is not wasted, given the reasonable (I think, for anyone wanting to prove me wrong, this is where I might be mistaken) assumption that the rate of dissipation of heat within the system is far greater than the rate of heat loss to the surroundings.

Re:Yea,

[Ullteppe]

The chemical definition of organic is (almost) anything that contains carbon. So, organic substances are not alive, and they don't die. That OLED displays have a short lifespan does not have anything to do with them being made of organic substances.

Ordinary LEDs do stop working eventually. Take a look at some of the early streetlights, you will see dead LEDs (somebody suggested they be called DEDs - Dark Emitting Devices). They have a finite lifespan, and gradually become more dim. That said, they will often last 10-20 years in ordinary usage.

Re:Yea,

[Inda]

They go pop. The first one to ever go pop in my house made me jump.

Don't pay for them in the UK. Your energy supplier will give you some for free if you ask.

Re:Yea,

[oldspewey]

power them with backup power systems when transmission lines are taken down by storms or drunk drivers. I will be able to light my workshop and outbuildings with waterproof potted LEDs instead of high-maintenance bulbs.

Tip: When storms and drunk drivers become a central factor in the way you plan your life, it is time to consider moving to a different neighbourhood.

Re:Yea,

[BigDogCH]

Wouldn't the mercury in the tuna be from our waste though? I think this is the same issue.

Re:Yea,

[BigDogCH]

If you put them on a dimmer, make sure the power is maxed. My parents have had several CFLS die, all on their lights that have dimmers. They will buzz and flicker more on a dimmer as well. When we remodeled, we didn't use any dimmers, because we have all CFLs. Will LEDs work on a dimmer?

Re:Yea,

[everphilski]

Me too. Frequent migraines. I have yet to have a migraine triggered by CFL's but I have had CFL's increase pain during a migraine. We have about half the lights in our house converted over to CFL's - but there are two rooms I will not put them in, my office and my bedroom, the two rooms I most likely be in during a migraine (either to finish work or to recover). Any other room I can avoid or not turn the lights on. The cost savings is great but even on a nice brand-name bulb, I perceive the flicker.

Re:Yea,

[drinkypoo]

LED lighting doesn't exceed the efficiency of fluorescent lighting in terms of lumens per watt yet.

Your description of the problem displays a level of ignorance which could easily be corrected by simply reading wikipedia. The simple truth is that there are numerous LED lights which are more efficient than flourescents, but there is a very good reason why the bulk of them are not.

This reason is that white LEDs are fluorescent lights. Not all of them, but all the cheap ones. That's because the alternative is to use multiple junctions in a package to produce a mixture of light to produce the whitest possible light. There are bicolor and tricolor (and for all I know quadcolor) LEDs, some of which are tuned for the closest thing you can get to white, and some of which are tunable.

The typical white LED is a blue LED (the most expensive single-color visible LED) doped with a material which emits yellow light when the blue light strikes it. This method does not produce the brightest light nor the whitest, but it is by far the cheapest way to produce a "white" LED.

The 3W mag-lite may not be more efficient than an imaginary flourescent that would produce the same amount of light, but they do illustrate a different point; the flourescent has a glass tube filled with toxic shit and a ballast to drive it. You can build the voltage regulation hardware right into an LED and just hook it up to some LVDC. I would be extremely amazed if the total lifetime energy cost of flourescent lighting were not significantly higher than that of LED lighting.

In short, [typical] white LEDs are not more efficient than fluorescent lighting because they are fluorescent lighting. When the cost of blue LEDs come down, and tricolor LEDs become more ubiquitous, then the price of the more-efficient "white" (in this case, tricolor) LED lighting will come down.

Re:Yea,

[somersault]

He could, if it weren't for the vicious homocidal storms and drunk drivers circling his town

Re:Yea,

[somersault]

Depending on how small the OLED's can be made

You do realise that you get OLED TVs and displays? A dimly lit pixel sized OLED will look pretty small when on your ceiling.

Re:Yea,

[pz]

High quality CFLs have a CRI of at least 98; 95 CRI is not what I, personally, consider high quality.

I cannot speak to the CFLs you have unless you want to share more details about them, but, in general, CFLs do not flicker anything near the frequencies humans can see. Traditional flicker fusion frequency, although highly dependent on factors like overall illumination, color saturation, and contrast, is about 30 Hz, give-or-take. There is, however, a large body of evidence that even higher order visual areas can be entrained at 135 Hz, although, mostly, we don't see anything much above 80 Hz in normal everyday life. (I am a neuroscientist studying the visual system.) Standard CFLs flicker at 40 kHz or higher -- yes, that's three orders of magnitude faster than we see, and two orders of magnitude faster than we have evidence that the visual system responds in any fashion at all. Flicker is not an issue for these bulbs when they are working correctly.

That said, I have, personally, experienced failing CFLs that audibly whine. These are clearly no longer working at 40 kHz. I can imagine that two CFLs in the same area might produce beating at a relatively low frequency (either audible or visible). But, also, bear in mind that ultrasonic sound waves alone can produce feelings of distraction and unease.

I suspect that you're experiences are due to something other than just a CFL blub alone, such as beating between two bulbs, or beating between the bulbs and your computer screen (LCD or CRT?), or something else.

Re:Yea,

[Anonymous Coward]

I'm abolutely not an expert but I know that today we can make LEDs that approach the light spectrum of an incandescent lamp.

LED's spectrum: http://home.att.net/~ledmuseum/specx05.htm
Incandescent: http://home.att.net/~ledmuseum/specx41.htm
CFL: http://home.att.net/~ledmuseum/spectra7.htm

The pale creamy white looking LEDs is already past technology, today we can make LEDs that looks translucent and I don't think those works with phosphor: http://www.lumileds.com/products/luxeon/

Re:Yea,

[somersault]

Do you often find yourself watching TV for 24 hours a day? Not disagreeing that it's not the best display life in the world, but it wouldn't be quite as dramatic as 6 months. And the type of person who is going to shell out $2500 for an 11" screen is probably going to get something better long before that one dies.

Re:Yea,

[drinkypoo]

And how freaking often do you break a CFL ?

I've broken two in the last year.

Ask a stupid question...

I think it's over 5 years since my parents and myself use only CFL and none broke.

The line to get your medal forms over there ---->

Seriously, the mercury inside a CFL lamp is anyway probably less than the mercury contained in 5-6 cans on tuna fish so stop with the stupidity.

Are you really this stupid? Where do you think that mercury comes from? It's not a byproduct of the canning process. It comes from humans overusing mercury, just as the organophosphates in the ocean come from humans overusing fertilizers and pesticides.

The typical counterargument about the mercury in CFLs is that the energy production typically involves coal which involves releasing mercury. But the LEDs involve less manufacturing than any CFL, so that argument is bullshit too.

CFLs are bad, LEDs are bad too, but less bad.

Re:Yea,

[somersault]

Either that, or they will switch to a different product..

Re:Yea,

[ivan256]

You're right in that I meant to say white LED lighting, since I assumed that's what we were talking about. My statement was only accurate in that context.

The rest of your comment, however, seems to be you reveling in the fact that you thought you were smarter than somebody. Classy.

Not only that, but part of it is just flat wrong. Multi-color white LEDs cannot yet produce a satisfactory white light and be more energy efficient (though they have successfully achieved one or the other). Making such a mistake displays a level of ignorance which could easily have been corrected had you simply read the Wikipedia article you mentioned.

For example, the dichromatic white LEDs have the best luminous efficiency (120 lm/W), but the lowest color rendering capability. Oppositely although tetrachromatic white LEDs have excellent color rendering capability, they often have poor luminous efficiency. Trichromatic white LEDs are in between, having both good luminous efficiency (>70 lm/W) and fair color rendering capability.

[note that 70 lm/W is substantially less efficient than a fluorescent lamp, which can achieve 100-110 lm/W]

Re:Yea,

[operagost]

He could, if it weren't for the vicious homocidal storms
When you're sodomized by a hurricane, you really feel it!

Re:Yea,

[commanderfoxtrot]

LED lights (and the cold-cathode ones) are very efficient at producing light.

However- if we all convert our lights to e.g. LED then we're losing 100s-1000s of watts of heating in the house.

So long as your central heating is more efficient than electric, you're fine- but the normal comparisons of lighting ignore the heating effect.

You could consider a normal lightbulb as a rather good heater of 90%+ efficiency :-)

Re:Yea,

[Astadar]

One could probably argue that this more or less balances out over the course of a year. I know I sure wouldn't mind 100s-1000s fewer watts of heating during the summer months.

So, savings in the summer, higher gas/electric bills in the winter.

It might also have the advantage of shifting some of the load off of the summer months, theoretically lowering prices, too. (I know that would probably only line the pockets of the electric cos.)

Re:Yea,

[james_orr]

What about the flip side though, how much COOLER would my house be in the summer? How much might I save in AC costs?

Re:Yea,

[Stewie241]

Wouldn't it be so much easier if we all just got used to everything being lit by red lights? Or blue for that matter? :)

Re:Yea,

[Stewie241]

Extra current will do it too... Ever tried to hook an LED up to a power source without adding a current limiting resistor?

Good times.

Re:Yea,

[Rutulian]

Yes, that's true. You're not supposed to use CFLs with a dimmer. There's not much point anyway. If you are dimming the lights, you aren't using as much electricity, and there isn't much advantage to using a CFL.

Re:Yea,

[GameboyRMH]

Will LEDs work on a dimmer?

If they're anything like any of the LEDs I've ever used, they sure will.

Re:Yea,

[BlackSnake112]

You have never had one burn out? I have had 5-6 burned out/blown in the past year alone. These were in 4 lamps and two ceiling fixtures. The old regular bulbs lasted 2-3 years. So far the longest CFL for me is 8 months.

Re:Yea,

[BlackSnake112]

If you own your place, try changing out the dimmers to regular switches?

7 diameter base? What kind of huge bulb are you replacing? That thing must weight a lot. Or do you mean a 7 foot diameter lighted area?

Why not a regular old timer instead of the light sensor? On at 6PM off at 6AM? Maybe you have to change it for daylight saving time twice a year. But no biggie. Those are either on or off so they should work with any kind of light that plugs in. I have seen wired in ones too but have not personally used any. So I can't speak as to how good/bad they are.

Re:Yea,

[DragonWriter]

However- if we all convert our lights to e.g. LED then we're losing 100s-1000s of watts of heating in the house.

Living in California's Central Valley, that's a big win: not only do you save on lighting costs, you save on air conditioning costs as well.

Re:Yea,

[Rutulian]

Nope. If your CFLs are burning out that quickly, you, A) have a shitty supplier, B) have extremely bad luck, C) have an electrical problem with your fixtures.

They will burnout eventually, but certainly not quicker than your incandescents.

Re:Yea,

[LunaticTippy]

Much of that heat is produced near the ceiling where it does no good. You have a higher heat gradient across your insulation but feel no warmer at people level.

Re:Yea,

[moosesocks]

How is this spam? I honestly don't understand the hate-fest people around here show toward this guy.

It's a legitimately interesting article; the summary is better-written than what the /. editors tend to come up with themselves; he makes no secret about who he is; and he's stopped hyperlinking to his blog, rather than the story in question.

Re:Yea,

[Anonymous Coward]

Agreed on most of your points, but the majority of white phosphor LEDs actually use blue emitters. See:

http://en.wikipedia.org/wiki/LED#Phosphor_based_LEDs

Sometimes this emitter is even visible as a bluish spot in the center of light cast by the LED.

Re:Yea,

[couchslug]

"Tip: When storms and drunk drivers become a central factor in the way you plan your life, it is time to consider moving to a different neighbourhood."

Those who do not plan for power interruptions are far less comfortable when they happen. It is really very easy to think ahead and keep ones arse covered.

Re:Yea,

[Anonymous Coward]

You should still use more efficient lighting, just more of it. The room will be brighter and all energy will end up as heat anyway.

Re:Yea,

[jonbryce]

Your gas/electric bill wouldn't be more expensive in the winter.

You would have to pay a bit more for heating, but if you use electric heating, this will exactly offset the savings on your lighting costs. If you use gas heating, it is almost certainly cheaper per kWh, so you would still be paying less.

Re:Yea,

[coolsnowmen]

Wouldn't it be so much easier if we all just got used to everything being lit by red lights? Or blue for that matter? :)

The problem is with that idea is that RED light won't illuminate BLUE things all that well (and vice versa).

Re:Yea,

[mazarin5]

I had problems with headaches and focusing with earlier bulbs, and I found that an effective solution was to have at least one incandescent in a fixture, with the other spots occupied by CFLs. It helps to smooth out my perception of the flicker. Also, CFL have different color temperatures, and mixing them up makes things even better.

Re:Yea,

[srussell]

LEDs have a long, long way to go before they can be used in living or working spaces.

Really? Because I just installed under-cabinet lighting in my kitchen, entirely from LEDs. It's gorgeous, and it doesn't melt the chocolate chips in the cabinets above like the fluorescent lights (it was probably the ballast or something) that I ripped out and replaced with the LEDs. I think it looks better, too.

These "good" CFLs of which you speak aren't available to Joe Consumer (i.e., me); the ones you get at Lowes are certainly a different spectrum and temperature than normal incandescents; I've got them throughout the house, and while they don't bother me, you can certainly tell the difference between them and the incandescents that are in the dimable fixtures. Oh, and that's my main beef with CFLs: you can't put them on a dimmer switch.

Incidentally, under-the-counter LEDs were expensive. I was willing to pay the price for the kitchen because I wanted low-profile, low-temperature lighting, but ouch.

--- SER

Re:Yea,

[Jorophose]

Sorry, I didn't word that properly.

By "die" I mean eventually be unable to work; it's not like decomposition death, if that's what you meant. And I haven't seen any LEDs from recent years fail in all sorts of tests. Of course they have a MTBF; but at 500,000 hrs+ it's definately not something you'll catch.

And of course, then what is the cause of the shortened lifespan of OLEDs? And I was wondering what the actual lifespan was; I remembered reading a site that said 4,000 hours but I figured that was way too short.

Re:Yea,

[somersault]

I never studied latin, you insensitive clod!

(homicidium, homo human being + caedere to cut, kill).

We're all homos in the end.

Re:Yea,

[Ullteppe]

For regular LEDs, they do lose brightness over time, but as you say this time is getting longer and longer. Usually, the lifetime is spec'ed as the average time where they have lost 50% of their brightness.

I'm not really that familiar with OLEDs, I saw some details on the Sony OLED TV, and they figured that it was going to last a few years of regular use (if you kept it on all the time, it wouldn't last long).

Personally, I think that OLED is going to be primarily a display technology for a long time. It has a long way to go before it can match the brightness of regular LEDs.

Re:Yea,

[kesuki]

everyone i know turns their heat down as cold as they can stand it in sweaters. if not using single room/person heating options.

lights that produce heat yeah that heat has to go somewhere, but a normal house doesn't have enough convection to make a difference in personal temperatures. take for instance a split level house that lacks doors (common design flaw people 'like' open floor plans) all the heat rises to the top floor, causing as much as a 10 degree difference between the top floor and the bottom floor, yes lights that produce heat make the TOP floor warmer, but the ones in the bottom floor help no one on that floor at all!

the only way to really benefit from the heat from an incandescent bulb is to sit above it where you WILL get personal heat, rather than minuscule heat at the ceiling.

people saying convection works, then why do ceiling fans have a winter mode? huh, in practice the only devices that can produce convection warming are baseboard systems. forced air won't, light bulbs won't you need a LOT of heat to make convection work.

besides, even if you live in alaska, in summer months the cooling bill increase from incandescent lights will more than offset any supposed benefit, in the winter. sure, you could have 2 sets of lights, one for summer and one for winter, or waste a lot of time changing (and breaking) bulbs.. the energy savings already offset the cost of some LED bulbs (especially if you have children, those unbreakable bulbs are a godsend)

mass producible, affordable, quality LEDs are nothing but good.

plenty of other ways to use electric heat. where i live, wood pellets are cheaper than electricity, for heating, not to mention corn burners, if you stock pile the corn in summer you can pay about 1% the cost of electric heat.

Is it white, though?

[neokushan]

I thought one of the major obstacles of using LED lights was that they weren't actually very white, but rather a shade of light blue? Has there been some major advance in creating white LEDs that I just happened to miss out on (serious question btw)?
And if so, just how white ARE these super cheap LEDs?

Re:Is it white, though?

[Anonymous Coward]

Why do you gotta be so racist against the blues!? Sheesh, white this white that. Sounds like you think white is superior in every way.

Re:Is it white, though?

[joaommp]

there are LED "light bulbs" based on sets of same amount of blue, green and red LEDs packed together. Those aren't a shade of light blue and some of them can actually be "tunned" to a desired color/tone for whatever purpose.

Re:Is it white, though?

[TheLink]

Many of these white LEDs are blue or UV LEDs that stimulate a phosphor coating to produce white light.

Having three Red Green Blue LEDs to create white light might produce a light that appears white to the eye, but might not have the same effect when reflected off material.

The white from the phosphor would generate more of a broad spectrum white, whereas the Red, Green and Blue LEDs would probably create spikes in the Red, Green and Blue spectrum.

So you might have a green material that appears black when you use the "RGB white" LED - just because it does not reflect the Green LED's narrow green, whereas it will appear green in the white from the phosphor white LED.

The phosphor means one more step in light conversion, and that probably means less efficiency.

Re:Is it white, though?

[that IT girl]

I am going to be very upset if I can't get incandescent anymore. Yes, they take more energy, but they are worth it... the bright white, unnatural light gives me a headache and causes my eyes to strain much faster when I am working under it for a long period of time. I never have this problem at home, with my "regular" lighting, only here at work under the fluorescents. I have heard this is at least partially due to the flicker rate. Would the LEDs pose this same problem?

Re:Is it white, though?

[gardyloo]

I would have absolutely agreed a few years ago. Traditional fluorescents hurt my eyes after a while, and incandescents are slightly warmer, and yellower, like natural light. However, the new compact fluorescents are awfully good, and with certain ones I can't tell the difference between them and incandescent bulbs.

Re:Is it white, though?

[Anonymous Coward]

Those are not really white. They only produce the sensation of white when you look directly at them or when they illuminate surfaces which evenly reflect the red, green and blue light of these LEDs.

People are so used to TV screens and computer monitors using RGB to create "all" colors that they think every light can be produced as a combination of red, green and blue. That is not the case. Most of the things that we look at are not light emitters. Reflected light however depends on the spectrum of incident light and the reflectance spectrum of the surface. You can shine RGB-white on a yellow surface and have it appear black, because the wavelength of yellow light which the surface reflects is not in the RGB white. Then the surface absorbs the red, green and blue light and appears black. That's why your mom told you to buy clothes only after you've seen them in daylight, because artificial light doesn't have the spectrum for exact color matching. Those pants which you thought were black may actually be a dark blue and not match your black jacket. Pay attention to your physics teacher and/or your mom.

Re:Is it white, though?

[sdpuppy]

Phosphor? Thats a bit disappointing. While I haven't followed the field much, I would have expected that they would have have come up with a way to make a variable band gap so you have electrons jumping back and forth over a wide range of frequencies.

Another thing I imagine might be to make the LED as an integrated circuit - an array of LEDS with each junction a slightly different gap than the preceding, so while you don't really get a true continuum, a few million different colors would be awfully close (and besides the frequency that an LED produces does have a band width, so if each color is close enough, you do get a continuum with enough colors.)

Anyone know if anyone is working on either method?

Re:Is it white, though?

[Anonymous Coward]

Guys, are you aware that they have white LED's? Check www.whiteled.net

This seems to be a change in the way that LED's are manufactured so as to make them more affordable, not to change the colors.

We use some white LED's at work, and they are very weak unless there are a lot of them in a bulb. How efficient are they when you have to use 100 of them to create the light of one 60w CFL is my question.

If anybody can point me to a good white light CFL that actually has a payback under 1 year, it would be appreciated.

Re:Is it white, though?

[Martin Blank]

LEDs are constant outflow, like incandescents. There is no flicker at all.

A lot of people who experience headaches under fluorescent bulbs are able to fix it by adjusting the refresh rate of their CRT screens, as the 60Hz flicker and 60Hz refresh rate can cause discomfort. If you have an LCD, you're out of luck, but if you have a CRT and can get a refresh rate of 75 or above, it may help alleviate the pain somewhat.

Re:Is it white, though?

[that IT girl]

I have an LCD monitor, in fact, I use the exact same one here at work as I have at home, because I wanted to determine what was causing my problem. After a few hours staring at this screen, my distance vision gets awfully blurry. A visit to the eye doctor told me my vision is fine but my eyes are getting strained, and I got some glasses to help reduce this. But at home, sitting the same distance from the same type of screen for the same amount of time, I have no trouble with the same distance vision. The only variable is the lighting.

Re:Is it white, though?

[funaho]

I too have a real problem with standard fluorescents, but I use CFLs almost everywhere at home and find them quite comfortable. They don't flicker and they have a warm, pleasant color spectrum.

Re:Is it white, though?

[De Lemming]

As far as I know, the most used variant is the blue LED + yellow phosphor one. In this case, the blue light, emitted by the LED, is cast directly, besides the yellow light coming from the phosphor. The mix of blue and yellow produces white light.

Unfortunately, these LEDs don't produce a very broad spectrum of light either. The spectrum has a sharp peak in the blue range, and a bit broader yellow range, as can be seen on this graph on the Wikipedia page.

Re:Is it white, though?

[shmlco]

"... the bright white, unnatural light gives me a headache..."

Yeah, because heating tungsten to over 2000 degrees K is so "natural" in and as of itself....

Re:Is it white, though?

[Arterion]

I don't get it.

First off, the color temperature of most "soft white" CFL's is not even 3000K. Normal incandescent bulbs give off light at about the same color. You can get "cool white" CFLs, though they are much less common, which give off light at around 4100K.

Both of these are much, much warmer than natural sunlight, which is usually over 6000K.

I see this argument a lot against CFLs, and fluorescent lighting in general. People describe it as "blue" or having an "unnatural color", but that's not really the truth.

What you ARE seeing as the problem is the difference between full-spectrum lighting and light that has a low CRI (Color rendering index). There's no clearly visible difference (as with color) between low CRI and high CRI (full spectrum) lighting, except that one causes your vision to feel strained.

Do yourself a huge favor and go to store that specialized in lighting, and find yourself a true full-spectrum CFL, and give it an honest try. The stuff they sell in supermarkets sucks, and I won't use them either. I would suggest a light about 5000K, because anything higher -- though it is truly more like natural sunlight -- will appear really, really blue when you compare it to the other light you'll see at night.

Re:Is it white, though?

[nmg196]

> LEDs are constant outflow, like incandescents.

No they're not. That's only true if you run them off DC.

This article is all about replacing light bulbs - and normal light bulbs run of AC, so LEDs will flicker just as much as florescent lighting. They're also diodes, which theoretically means that they would normally flicker twice as much. However I think they put two sets of LEDs in to counteract that effect and probably some voltage smoothing capacitors.

Re:Is it white, though?

[AaronW]

That's a good question. The white LEDs are often blue LEDs with a phosphor. The bright ones use a di-chromatic phosphor which gives a lower color rendering index. There is more information at Wikipedia.

Re:Is it white, though?

[kesuki]

you do realize, that except for lighting, and simple fans, virtually everything requires DC power to run.

so putting in a rectifier into lighting doesn't add $10 to the cost of a light bulb, it adds about $2.

in order for LEDS to be energy efficient, they require rectifiers anyways, since they only stay on 35% of the time when run straight off AC current. besides, to perform dimmer functionality an IC that can switch the power on and off rapidly is needed, and it's easier to put it in the bulb.

and some people aren't bothered by flicker, I for one have a very low sensitivity to flicker. I've had headaches from using older style CRTs but only when i was 'changing' my viewing behavior, eg: vacations away from the PC i'd be prone to headaches from not being around the flicker, and maybe when i first got back to staring at a monitor all day.

OTOH, i easily get headaches from both caffeine, and aspartame. oh yeah, and i'm very near sighted, perhaps my lack of sensitivity to flicker has something to do with the quality of my optical inputs.

Re:Is it white, though?

[Kneo24]

Hey man, do you really want to be a smurf? You know, a group of whatevers that has only chick in it? If everyone else is hitting it, do you want to hit it too?

Re:Is it white, though?

[Teriblows]

not very currently, and they require large heatsinks that look rather like giant cpu heatsinks to keep the leds cool enough to last for any reasonable period. and thats the problem so far, its not affordable. its not just manufacturing price but efficiency. leds cannot survive heat.

Re:Is it white, though?

[Your Pal Dave]

You should have paid more attention to your biology teacher. The reason that RGB works in the first place is that the cone cells in your eyes perceive colors in terms of red green and blue, not in a full spectrum.

You may as well argue about sources lacking IR or UV components of light. Unless you happen to be tetrachromatic it's all invisible.

Re:Is it white, though?

[falconwolf]

the bright white, unnatural light gives me a headache and causes my eyes to strain much faster when I am working under it for a long period of time.

The unnatural light from incandescent lights?

I never have this problem at home, with my "regular" lighting, only here at work under the fluorescents.

I've never had problems with CFLs, the only florescent lights I have had problems with were the old 4' tubes in offices, factory floors, and sales warehouses.

Falcon

Re:Is it white, though?

[Koookiemonster]

I never have this problem at home, with my "regular" lighting, only here at work under the fluorescents. I have heard this is at least partially due to the flicker rate.

Fluoroscent lights with electronical ballasts flicker at 20 000+ Hz instead of the 100 or 120 Hz with traditional ballasts. Such a high frequency seems as if they don't flicker at all. CFL's have electronical ballasts.

Incandescent bulbs can flicker too. The voltage is alternating between -325 V and 325 V (in Europe) - simplifying a bit the voltage is sometimes 0 volts, the filament cools down just a bit, and it gives less light. How much less is beyond me - perhaps it's just marketing hype.

Re:Is it white, though?

[TheLink]

The AC is right. Go read it again - the AC is talking about _reflected_ light. Not looking at the light directly.

The light from typical RGB LEDs is narrow band.

A material that looks blue in sunlight could look a lot darker in the "white" LED light if it does not reflect the narrow band blue from the blue LED. It might even look black as the AC says.

Re:Is it white, though?

[that IT girl]

As opposed to the sun, which is heated to between 11,000 and 27,000,000 degrees F and produces the natural light that has sustained us for millions of years. :) (Or thousands, depending on your idea of how we got here.)

carbon-free daytime lighting

[Anonymous Coward]

With the cost of solar cells and LEDs plummeting, a solar cell roof installation with closed-circuit LEDs might soon become cheaper than a ceiling window.

Re:carbon-free daytime lighting

[4D6963]

With the cost of solar cells and LEDs plummeting, a solar cell roof installation with closed-circuit LEDs might soon become cheaper than a ceiling window.

What do you know! Soon enough it'll all get so efficient that with closed-circuit LEDs shining on solar cells you'll be able to make your own infinite source of energy!!

Oh shit that's a hell of good idea! The first one to the patent office wins!!

Re:carbon-free daytime lighting

[Anonymous Coward]

You do know it costs a huge heap of cash to cut a whole out of your roof and install a piece of glass, right?

Re:carbon-free daytime lighting

[genericpoweruser]

That's a great idea! I'm gonna be mounting a wind power generator on my car to improve gas mileage. I don't think it'll get all the way to infinite but I bet I could easily get a good 300-350MPG out of this thing!

Re:carbon-free daytime lighting

[ubercam]

You laugh, but your idea isn't far off from an actual real-life system.

http://www.building.co.uk/story.asp?storyCode=3085046

Not exactly the same one I saw on TV, but very similar. Basically it's a sort of satellite dish sized collector that follows the sun around all day. The dish is focused on a point that has a UV filter, and from there fibre optic lines are run from the collector to the various parts of your building/house and are used to supplement the existing electric light system. Obviously only useful during the day, but the makers were saying that people felt better working inside because there was natural sunlight (minus UV) indoors.

The system in the link is said to use 2W/day.

Very neat stuff, but would it not have to be tied to a light meter to flick on the regular lights when a thick cloud passes over or something. I believe they still work just fine on an overcast day.

Re:I heard

[Anonymous Coward]

That Roland enjoys fellating men.

Only Timothy.

Light vs. heat scale

[WhoIsThePumaman]

I'd be interested to see a progression timeline of the light vs. heat ratio from the various methods we've used. I'd imagine candle and torches would be the heaviest on the heat side, but seeing it slide with gas lamps, lanterns, incandescents, CFLs, and now LEDs would be neat. Anyone have some spare time on their hands?

Re:Light vs. heat scale

[Anonymous Coward]

Here: http://en.wikipedia.org/wiki/Luminous_efficacy#Lighting_efficiency

Re:Light vs. heat scale

[rcw-home]

I'd be interested to see a progression timeline of the light vs. heat ratio from the various methods we've used.

Here you go. To convert lumens per watt to an efficiency ratio, divide by 680 (1 watt of pure green light - the kind the eye is most sensitive to - is 680 lumens).

Note three things:

1. Incandescents are nowhere near the 10% efficiency mentioned in the article summary. Maybe 5-6% for the better halogen/xenon bulbs.
2. Not mentioned on this chart is CRI. Lighting sources below roughly 70 CRI are often considered undesirable for residential indoor light.
3. Efficiency and CRI are often a tradeoff.

Re:Light vs. heat scale

[Taibhsear]

Anyone have some spare time on their hands?

This is slashdot. Everyone has spare time on their hands...

LED = Luxury Goods

[cdrguru]

Take a hint from the car manufacturers. Today, high-end cars are using LED tail lights. They are also used on trucks. The main advantage is they do not burn out.

However, for most people in the world a burned-out tail light bulb is a minor safety issue and a minor expense. Replacing the bulb takes 10 minutes and maybe the owner's manual if you are truely clueless about how to do it. Also, many people own a car for 5+ years without ever having to replace a single bulb.

Compare this to the cost of a minor traffic accident where a tail light is cracked. No, you cannot replace the lens or any individual part, just the whole assembly. Instead of $100-$200 for an incandescent bulb assembly expect to pay $1500-$2000 for the LED tail light.

Sure, over the life of many vehicles it is a minor issue that bulbs will never burn out. But over the same number of vehicles it is far, far more likely that a lamp assembly will have to be replaced. The result is a far more expensive part to replace.

With trucks there is a certain amount of sense to be made with claiming that the bulbs do not have to be replaced. Replacing a bulb on a truck or semi-trailer can be a real hassle requiring a ladder and tools. However, again the likelyhood the bulb would ever need to be replaced vs. the lens being damaged is about the same as for cars. Basically, it is a complete rip-off.

Expect to see wired-in LED systems in household lamps where the fixture must be replaced because the bulbs cannot be. Expect to see the fixtures sold to builders with non-replacable bulbs will cost the builder only slightly more when bought in huge quantities but the homeowner will be faced with $1000 lamp fixtures should they ever need or desire to replace them.

Re:LED = Luxury Goods

[failedlogic]

This is certainly an interesting post and a consequence most of us probably haven't considered yet. I'm definitely going to check before investing in any of these lamps how easy it is to replace the light or if its the entire fixture. Kind of kills the whole idea of environmental friendliness. If some manufacturers choose to do this, I will boycott their products.

Re:LED = Luxury Goods

[ModernGeek]

I have noticed that with LEDs, they are brighter than a comparable halogen bulb + filter, but they do not light up the surrounding area as well. I have an LED lightbar on top of my vehicle (volunteer firefighter), and the lights are brighter, but compared to a halogen lightbar, it does not light up the area with red and white the same. It is definitely more visible though. That is why I think LEDs might be good for taillights and such, but probably not for headlights.

Re:LED = Luxury Goods

[Sleepy]

Sure, you might see some applications "soldering" he LED right into the housing... just like it's done with some CPU & motherboard applications.

If people want bulbs, though, they will get them. There's no monopoly on LED bulbs, and no builder conspiracy to require us to get non-servicable lights.

The cost of manfacturing LEDs in a bulb fashion is cheap -- not much different than regular incandescents. The big holdup and cost is it takes too damn many bulbs to accomplish the lumens.

You'll probably always need more than 1 LED to make a bulb, simply because the LEDs are very 'directional' instead of 'point' lights. But today's LEDs are weak and expensive, so instead of getting by with say 8 LEDs, you need like 50-100 for a omnidirectional light.

I have a few of these in spotlight form. The $8 20 LED ones make great desk and reading lamps (or killer nightlights if you want to keep another room lit at night). The ones that compare to regular bulbs are $35-$100 and at that price, I'm not willing to get one even as a test.

Another technology to watch is CCFL -- Compact Cold Fluorescent Lighting. Right now it's mostly used in PC cases by the LAN party kids, but it's starting to be used in bulbs.

Re:LED = Luxury Goods

[jlanthripp]

Trucks use LED taillights because they are more visible in the daytime. It never ceases to amaze me how often a 4-wheeler (car driver) will rear-end a truck that is braking for a stoplight or turn, then claim that they didn't see the truck's brake lights.

The LED taillights you see on a lot of semi-trailers are held in place by metal bezels that are riveted in place by the manufacturer. To replace one, you have to drill out the rivets. Then of course you can simply use self-tapping screws to put the bezel back on once you have replaced the light. Incandescents tend to be held in place by a rubber cup-like thing that I don't know the name for, and can be removed by prying on the light with a flathead screwdriver, much like dismounting a tubeless tire from a wheel.

The reason for riveting the things in place is to deter theft. Incandescent lights don't get stolen nearly as often as LED's for some reason.

Re:LED = Luxury Goods

[sdpuppy]

Interesting post, and I don't doubt that built-in fixtures will be produced.

Now for cars, don't forget that it is assumed that people who buy the high end cars don't care about paying extra $$ to get their car repaired (true or not) - and whether it costs significantly more to change a high end light (well it is so much more highly styled)

If you do care about costs, and don't own a fancy smancy car, you can still reap the benefits of LED signals.
A visit to a local Pep Boys store shows that you can buy a standard incandescent turn signal bulb or a new fangled LED turn signal bulb which fits in the same socket.
So the rich or style-conscious will buy the expensive to maintain stuff and the rest of the grunts will buy the utilitarian LED bulbs that screw/bayonet into standard fixtures.

Re:LED = Luxury Goods

[Anonymous Coward]

Take a hint from the car manufacturers. Today, high-end cars are using LED tail lights. They are also used on trucks. The main advantage is they do not burn out.

However, for most people in the world a burned-out tail light bulb is a minor safety issue and a minor expense. Replacing the bulb takes 10 minutes and maybe the owner's manual if you are truely clueless about how to do it. Also, many people own a car for 5+ years without ever having to replace a single bulb.

Compare this to the cost of a minor traffic accident where a tail light is cracked. No, you cannot replace the lens or any individual part, just the whole assembly. Instead of $100-$200 for an incandescent bulb assembly expect to pay $1500-$2000 for the LED tail light.

Sure, over the life of many vehicles it is a minor issue that bulbs will never burn out. But over the same number of vehicles it is far, far more likely that a lamp assembly will have to be replaced. The result is a far more expensive part to replace.

With trucks there is a certain amount of sense to be made with claiming that the bulbs do not have to be replaced. Replacing a bulb on a truck or semi-trailer can be a real hassle requiring a ladder and tools. However, again the likelyhood the bulb would ever need to be replaced vs. the lens being damaged is about the same as for cars. Basically, it is a complete rip-off.

Expect to see wired-in LED systems in household lamps where the fixture must be replaced because the bulbs cannot be. Expect to see the fixtures sold to builders with non-replacable bulbs will cost the builder only slightly more when bought in huge quantities but the homeowner will be faced with $1000 lamp fixtures should they ever need or desire to replace them.

I smell some FUD

As for the replacement cost of a LED light component on a car. I personally can replace BOTH left and right sides of my cars LED light assemblies (which consists of 4 separate pieces) for $450. The leap from incandescent assemblies is only about $100. And yes, this is OEM, not a 3rd party solution. And to top this off, it takes about the same 10 minutes to replace these assemblies.

As for it being a complete rip-off, the odds of it needing to be replaced is not the only implication. Most LED components on cars that I know of are more visible, take lest time to be "on." Additionally, they draw less current thus putting less strain on the power generation and results in a slight efficiency and MPG boost.

From a build-out perspective you can even use smaller, more compact alternators that don't need to put out as much energy to run conventional lighting. I don't know much about the LED's manufacturing process but suspect you get a smaller carbon footprint there too as you don't need to melt a bunch of glass to make bulbs with... etc.

Even tho I am not a tree-hugging sprout-munching environmentalist, I can see the bigger picture with LED lighting.

Re:LED = Luxury Goods

[sdpuppy]

Solution - make the LEDs as an array/matrix on a chip, similar to the way CPUS are made now. A million or so LEDs glowing should be fairly bright.

Re:LED = Luxury Goods

[hardburn]

Car LED fixtures have huge margins. In fact, for the turn signals and brake lights, they should be dirt cheap since they're monochromatic.

You can get white LED lights for incandescent fixtures right now for about $20. CFLs are still probably more economical, but LEDs are catching up.

Re:LED = Luxury Goods

[Anonymous Coward]

I bigger gain is that LED tail lights light up faster then incandescent ones. The sooner the guy behind you starts stopping the better chance you have to avoid the accident.

Re:LED = Luxury Goods

[Anonymous Coward]

I've had to replace a couple of bulbs in my car. Each time I had to remove the bulb, drive to the store, drive home, replace the bulb. Factor in my time, fuel, and the cost of the bulb, and it's not quite as cheep as you make it out to be. Factor in ALL of the people around the world that have to do exactly the same thing and you'll see it adds up rather quickly. Also, you argument about fixtures costing $1000 is pretty out there too.

Re:LED = Luxury Goods

[BlueFireIce]

Compare this to the cost of a minor traffic accident where a tail light is cracked. No, you cannot replace the lens or any individual part, just the whole assembly. Instead of $100-$200 for an incandescent bulb assembly expect to pay $1500-$2000 for the LED tail light.

LED tail lights are far from the $1500 range. Just look at all the aftermarket tail light kits out there, allot of them are even cheaper than OEM replacements. And in most tail light set ups you CAN just replace the lens housing, as the bulbs twist in. And many LED tail lights are going the same route to where they can be more readily replaced.

The only time you are going to see a 1500+ price on a light is on high end cars such as Mercedes, we had one in the shop just a few weeks ago and the headlights ran 1200 each (and that's shop cost). Luxury car tail lights don't cost allot because of the LED's in them but because they are high end cars and the owners can afford to shell out the money for it.

Re:LED = Luxury Goods

[Anonymous Coward]

The other reason LEDs are used in taillights is because the reach full brightness a lot faster. If I remember correctly, it means the driver behind you would come to a stop about 5 feet sooner at 30 MPH. That could mean the difference of whether you have to peel a Ford Focus off your bumper.

Re:LED = Luxury Goods

[noidentity]

cars are using LED tail lights. They are also used on trucks. The main advantage is they do not burn out.

I thought their main advantage was that they light faster, reducing the time from brake pedal to the driver behind you seeing them light.

Re:LED = Luxury Goods

[Jeff DeMaagd]

Other parts of your post have already been picked apart, but what's the failure mode for home LEDs? There are LEDs that can screw into the same type of bulb sockets as the incandescents.

I don't see how truck lights are necessarily damaged as often they would be on cars, as you contend. The lights on a truck are up higher, and in a collision with a typical passenger vehicle, high enough that it would have to be serious. Lighting up faster and being more visible should help reduce the number of accidents and reducing their severity.

The cost of LEDs are going down, and if first party replacements are needlessly expensive vs the cost of the parts, I would expect the aftermarket to come up with cheaper solutions.

Re:LED = Luxury Goods

[xaxa]

They are. I've seen some in nightclubs and at concerts, the brightness and the instant on/off effect is fantastic.

It's probably even better with ecstasy.

Re:LED = Luxury Goods

[the eric conspiracy]

Even finding a CF bulb with that low an output would be difficult. A typical 1300 lumen CF bulb goes for less than $2 these days.

Re:LED = Luxury Goods

[pimpimpim]

Same here. When I drive behind a car with LED taillights, the focussed light of the LED creates a memory effect in my eye and the spots remain visible even when I blink. This is very irritating, because natural instinct tells my eyes to focus on the bright spots, and it makes it difficult for me to focus on other traffic. I for one, hope that LED tail lights remain a luxury good for quite a while to come ;)

Re:LED = Luxury Goods

[NormalVisual]

I have an LED lightbar on top of my vehicle (volunteer firefighter), and the lights are brighter

Yeah, I'll definitely agree they're brighter. I think they're brighter to the point that the light bar manufacturers should incorporate a photocell that will allow the controller to reduce the LED duty cycle when it's dark outside because they're dazzling to the point of ruining dark-adapted vision, particularly the blue ones.

Re:LED = Luxury Goods

[Anonymous Coward]

So order a box of 10 of them at a time online. With shipping, that should be about $15.00 or so, and you'll have a set of ready spares whenever one burns out. A box of 10 should last for many, many years.

Re:LED = Luxury Goods

[Daniel_Staal]

There is another reason for the switch to LED taillights: They react faster. Pull up behind a car with a LED center light and standard outer lights, and you'll be able to notice that when they brake the center light comes on first. The extra few milliseconds can help. That, the fact that you can form different shapes of lights, and the lower power consumption (a concern in cars, where a lot of cars are near the max for their electrical system, with all the gadgets these days...) will all push for more LEDs in cars.

Re:LED = Luxury Goods

[SeaFox]

However, for most people in the world a burned-out tail light bulb is a minor safety issue and a minor expense.

I'm rather happy to see the change to LED back-lighting on cars. I can't count the number of times I've found myself driving behind someone with NO rear lights, because the vehicle relies on a single pair of double filament bulbs for tail light, break light, and turn signal functionality all at once. These same vehicles (which are generally American-made) don't feature a bulb monitoring systems like imports have for twenty years now that tell you when a light has gone out.

It may sound like a luxury feature, but people are generally too lazy to check the simple things on their cars, if tire inflation studies are any indication. Small things that affect safety of other drivers on the road. Automatic headlights weren't added just for consumer convenience. They mean fewer drunken idiots driving with no lights, and people not getting stranded because they forgot to turn off their lights and drained their battery.

Re:LED = Luxury Goods

[kesuki]

"Compare this to the cost of a minor traffic accident where a tail light is cracked. No, you cannot replace the lens or any individual part, just the whole assembly. Instead of $100-$200 for an incandescent bulb assembly expect to pay $1500-$2000 for the LED tail light."

umm, where do you come from. a LED costs about $.75 cents TFA is quoting prices of 'after market light bulbs' at the $100 range, and even that is unrealistic, the places i shop online a good quality LED light costs $35-75, and that's for at least 100 watt equivalence.

TFA suggests that someday LEDs based on mass produced silicon wafers will be cheaper than existing tech which relies on sapphire.

seriously, where did you pull the $2,000 price tag from, because no honest vendor is going to charge you 2 grand for LED replacement lighting even if the whole fixture is bad.

Re:LED = Luxury Goods

[iksbob]

LEDs don't have to be directional, they just commonly are. Using a large electrical contact to heat sink the emitter die (as is generally done) means that light output is limited to 180 degrees. Most high power LED manufacturers leave it at that by simply putting a dome over the emitter, leaving light collection and focusing to external optics. Smaller component LEDs don't have enough output to be effective for area lighting, and external optics for each emitter would consume a lot of space. As such, the manufacturer will often shape the heat sink/contact into a cone which focuses the light in a general direction and then profiles the plastic casing so it acts as a lens, focusing it further.

Oh, and CCFL stands for Cold Cathode Fluorescent Lighting - it's been in use as LCD backlighting for ages.

Re:LED = Luxury Goods

[smellsofbikes]

For what it's worth, one reason trucks have gone to LED's is that they don't die because of vibration, like incandescent bulbs do. We don't really know how long LED's will last, but if they're correctly designed, they should still have at least 50% brightness at 50,000 hours of operation.

All the LED lighting solutions my company is building, and all the ones from our competitors that we've been buying and taking apart, are screw-in replacements for existing bulbs. Every single one, without an exception. If car companies wish to make their cars more proprietary by specifying custom LED lights, well, they're free to, but I think it'd be a stupid move.

Re:LED = Luxury Goods

[Kneo24]

Yes, I've noticed that too. They look significantly brighter and hurt my eyes when driving. I've even got the occasional migraine from the fucking light reflecting off my side view mirror at just the right angle to pierce my my brain and give me a massive migraine. It's pretty much the only reason why I hate driving at night.

Re:LED = Luxury Goods

[mr_walrus]

however, we do NOT use LED lighting on our snowplows because
they are not warm enough! warm incandescents tend to keep the snow
melted off over the lamp area, LED lamps just let the snow build up
until the lamp is no longer visible.

this would apply to any truck or car too.
but plows generally only go out when the weather (and visibility)
is the worst.

you'd be surprised how many people collide with snowplows (with
ALL their many flashing lights, etc) because they claim to not
seem them. (in truth they are just driving too fast.)

my own personal experience indicates perhaps there is too much
flashing light activity on a plow. nobody seems to notice turn
signals for lane changes. the little flashing turn signal lamp
i suspect disappears into all background noise of the many
flashing beacons on the equipment.

Re:LED = Luxury Goods

[Anonymous Coward]

LEDs turn on a lot faster than normal lights which is why they are used in cars.
Nothing to do with their burn out rate.

Re:LED = Luxury Goods

[Jorophose]

Speaking of desks, you know what would be nice?

LEDs or OLEDs sandwhiched inbetween two sheets or glass or plastic, in desks. Seal it to make it waterproof, with a small switch. Flick it on, your entire workspace is illuminated.

Or even better, give it sensors, for touch. When you touch it and draw something, the LEDs in that path light up to match it. When you press a button on the side it gets "erased", and another one possibly to "lock" (temporarily of course). So, need some light to read those docs? Just draw out a lamp, and avoid it coming from under the paper.

Considering LEDs should pretty inexpensive, it would be an interesting experiment.

Re:LED = Luxury Goods

[Anonymous Coward]

you've never seen an aspheric Maglite modification using a Seoul Semiconductor P7 LED. The SSC P7 produces about 700-1000 lumens when driven properly, though lower levels are a bit more efficient and lead to longer emitter life, but to make the math easier I'll say we use a slightly higher drive current to get 1000 lumens at the emitter. That's about what a 60-watt bulb produces for a third the electricity. Two problems: LEDs produce mostly blue and yellow light, and SSCs also produce a good bit of green when they get hot. Red light is important for contrast, and if you want to get things back in balance, I'm told you need a ratio of one red to four white LEDs. This has the problem of not artificially enhancing contrast like incandescent lights do, and we've all become accustomed to that enhancement.

The other problem they have is efficiency - a good reflector/window can be better than 90% efficient, but most are within 60-80%, and 70% can be assumed. This means 700 lumens out the front of a light. Now, to bring this together - LED lightbars I've seen have no collimating optics, just a bare emitter under a plastic protective layer. All the light comes out as a flood, with no focused spot. The other extreme is the aspheric lens I mentioned earlier, which can collimate effectively all the light coming out of the business end of the light into a focused spotlight. Thing is, a lightbar is meant to be seen, not to illuminate; most squad cars have a manually-operated, built-in spotlight for that.

And yes, you're probably right about the not lighting up the surroundings well; I blame the lack of even a basic reflector that halogen signal lights use, and the red-deficient spectrum put out by white LEDs.

Re:LED = Luxury Goods

[couchslug]

"Replacing a bulb on a truck or semi-trailer can be a real hassle requiring a ladder and tools. However, again the likelyhood the bulb would ever need to be replaced vs. the lens being damaged is about the same as for cars. Basically, it is a complete rip-off."

Bulbs on semis lead a VERY rough life, and the DOT requires that all lights work (including markers) or it's a violation with a ticket to match. LEDs are usually potted and not in a socket subject to vibration (that wipes the solder nubs off conventional bulbs).

"but the homeowner will be faced with $1000 lamp fixtures should they ever need or desire to replace them."

As LED form-factors stabilize over time this should be easy to sort out with a soldering iron.

Re:LED = Luxury Goods

[Anonymous Coward]

Where in the hell do you get your LED tail lights? For $2,000, I could replace all the lights in my vehicle with LED lights, and redo my entire paint and body with the leftover change. :P

Re:LED = Luxury Goods

[budgenator]

I would also expect that losing one LED doesn't knock out the whole array. If a truck loses a taillight on the road, the driver pulls over and calls for an emergency repair truck, a very expensive proposition but losing one LED out of a 50 LED array is no big deal.

Re:LED = Luxury Goods

[shiftless]

Take a hint from the car manufacturers. Today, high-end cars are using LED tail lights. They are also used on trucks. The main advantage is they do not burn out.

I've seen plenty of cars and trucks driving around with several LEDs burned out in their tail lamps.

Re:LED = Luxury Goods

[Anonymous Coward]

One of the advantages to LEDs versus filament-based brake lights is the response time of the bulb. Milliseconds go by as the filament gets hot enough to glow, whereas LEDs produce light almost instantaneously.

I know there's supporting evidence of this, but I'm posting under AC, to I'm feeling pretty lazy right now.

Re:LED = Luxury Goods

[jlanthripp]

I would also expect that losing one LED doesn't knock out the whole array. If a truck loses a taillight on the road, the driver pulls over and calls for an emergency repair truck, a very expensive proposition but losing one LED out of a 50 LED array is no big deal.

Stopping a 8'6" wide vehicle on a 9' wide shoulder of a major highway for a couple of hours until a repair truck manages to show up because of a single taillight going out is insane. Far safer to drive the truck, with one taillight out, to the next truckstop for a new light (or pull into the next rest area to replace the light with the spare a prudent truck driver carries in his toolbox). The only time any responsible trucker pulls a truck over to the shoulder and calls a road service truck is for a problem arising during operation that makes it physically impossible or extremely unsafe to move the truck, such as a flat steer tire (now there's a ride with lots of pucker factor, losing a steer tire on an 18-wheeler at 65-70mph...those tires each carry more than the weight of a full-size SUV), loss of air pressure in the brake system, total engine failure, etc.

Re:LED = Luxury Goods

[Teriblows]

sounds good, except that the heat of an array of powerful leds would fry the thing

Re:LED = Luxury Goods

[syukton]

CCFL stands for Cold Cathode Fluorescent Lamp. You may be confusing it with CFL, which is simply Compact Fluorescent Lamp. Just clarifying.

Re:LED = Luxury Goods

[FrankieBaby1986]

One factor in the choice to use LED's for taillights is also the reaction time. LED lights come to full brightness (and in THEORY) can cut back the reaction time if several cars in a chain must stop quickly.

Re:LED = Luxury Goods

[Whiteox]

Also, many people own a car for 5+ years without ever having to replace a single bulb.

You've obviously never owned a Volvo.

Re:LED = Luxury Goods

[Sleepy]

Yep exactly. "Cathode" was in my head, but not what was typed.
Still, neat stuff!

Re:LED = Luxury Goods

[wesborgmandvm]

Expect to see wired-in LED systems in household lamps where the fixture must be replaced because the bulbs cannot be. Expect to see the fixtures sold to builders with non-replacable bulbs will cost the builder only slightly more when bought in huge quantities but the homeowner will be faced with $1000 lamp fixtures should they ever need or desire to replace them.

I am not concerned. The free market will take care of your hypothetical issue. Some one will buy huge replacement quantities and sell individual fixtures at a fair mark up.

Re:LED = Luxury Goods

[Anonymous Coward]

Replacing a bulb on a truck or semi-trailer can be a real hassle requiring a ladder and tools. However, again the likelyhood the bulb would ever need to be replaced vs. the lens being damaged is about the same as for cars. Basically, it is a complete rip-off.

Except on commercial trucks, the LED tail and marker lamps are not trying to be "pretty" and integrating seamlessly, like on that shiny new car.

Accordingly, you can get Piranha LED assemblies for almost nothing, because they're trying to fit a standard mounting size (2" round, 3" round, 2x5" oval, whatever).

It's not the LED that costs more, it's the seamless integration and the single source that makes it cost more. While you may be able to buy a third part body panel (stamped steel!), I can't think of any third party manufacturer who is going to want to get into the business of cranking out finicky DOT approved low-volume repair parts. Molds are expensive!

Re:LED = Luxury Goods

[grandbastard]

... Expect to see the fixtures sold to builders with non-replacable bulbs will cost the builder only slightly more when bought in huge quantities but the homeowner will be faced with $1000 lamp fixtures should they ever need or desire to replace them.

I have several LED fixtures. I don't think I've spent much more than $60 on one. Backwoods Solar has a selection of them.

Re:LED = Luxury Goods

[sdpuppy]

Heat problem of a matrix could be handled in a variety of methods that are commonly used to save power with discrete LEDS, just built into the chip so that its idiot proof- by flashing alternate (or flashing with gaps), each LED could be fairly low power (but with so many light output would still be good) and so on.

Re:LED = Luxury Goods

[Anonymous Coward]

Yes, because everything is better while you are destroying your mind and body with drugs.

Re:LED = Luxury Goods

[moosesocks]

Lighting geek here.

LEDs are having a tough time competing with incandescent and HID fixtures for a few key reasons.

They're not nearly as bright as their incandescent counterparts. An incandescent PAR64 can inexpensively produce a ridiculously bright loosely-focused beam at very low cost. HID fixtures are even brighter. LEDs simply cannot compete.

HID and Incandescent fixtures can easily be focused into a tight beam. LEDs cannot. Their uses are currently limited to LED-PAR64s, key lighting, and matrix-type displays for effects and/or video display.

The color temperature of LED fixtures doesn't quite match up with what you'd get from an incandescent bulb. Using them together either requires gelling the LEDs to be the same temperature as the incandescent bulbs, which is usually simply not worth the bother.

HID (High Intensity Discharge) fixtures have gained a high degree of acceptance, despite their high price, especially in intelligent and robotic fixtures. Although they cannot be dimmed, most are fitted with a "mechanical" dimmer and a shutter mechanism for a similar instant on/off effect, or strobing.

LEDs have their uses, but for theatrical/concert/club usage, they're still very much a niche market due to these drawbacks.

Re:LED = Luxury Goods

[IdeaMan]

Duty cycle?! I saw that the other week. Some new car used 100% for brakes, some lower duty cycle for running lights. The thing is, when you turn your head or move your eyes, they strobe like crazy. The frequency they run em at better be in the kilohertz range.

Don't market these in Boston

[LM741N]

They really have a phobia about LEDs there- especially if there are wires attached like an AC cord.

Your lack of intelligence is shining brightly

[A nonymous Coward]

Dipshit. You could have come up with all sorts of bigoted Asian jokes since sunlight is not white but yellow. Instead you spew about Jews and blacks. Heck, even a joke about uv light would have been more interesting.

You are pathetic and have no imagination.

Re:Your lack of intelligence is shining brightly

[LS]

sorry to break this to you but the main component of sunlight is actually green

It's Roland the Plogger, wrong as usual

[Animats]

It's so Roland the Plogger.

1. Find some minor advancement in materials science.
2. Hype it as big breakthrough.
3. Post on Slashdot.
4. Direct traffic to ad-heavy blog.
5. PROFIT!

The "breakthrough" this time is that someone made gallium nitride substrates that might, someday, be useful for LEDs. After they solve the problem that their material cracks during cooling. However, Panasonic did that last year, and has been shipping white LEDs using that approach in sample quantities.

Re:It's Roland the Plogger, wrong as usual

[Anonymous Coward]

The article you link is about growing on a GaN substrate, not Si as the Purdue team is doing.
Growing on GaN is probably even better (the substrate is the same material as what you're growing), the trick has always been being able to grow large amounts of GaN in a time and cost-effective way.

The Purdue work is interesting, but they're downplaying some significant hurdles. They note that using silicon allows for much larger substrates (Si substrates are now reaching 450 mm, Saphire is just making 100 mm), but the stain problems (such as cracking when cooling) are just worse when you go to larger substrates.

Re:It's Roland the Plogger, wrong as usual

[Anonymous Coward]

• Direct traffic to ad-heavy blog.
• PROFIT!

Good theory. Except, TFA is on Purdue.edu, not a blog...

Re:It's Roland the Plogger, wrong as usual

[nasor]

Uh...the linked article is on a purdue.edu page and has zero adds. Am I missing something?

Re:It's Roland the Plogger, wrong as usual

[Anonymous Coward]

You're missing the "Roland Piquepaille" link just on top of the summary.

Re:It's Roland the Plogger, wrong as usual

[dkf]

It's so Roland the Plogger.

So? He writes things up a lot better than most of the submissions. I have seen the Firehose, and Ye Gods! most of the stuff is badly written. If you want no more Roland, why not do some good (i.e. well written, informative) submissions yourself? It's not that hard, and you can pick a subject that you're an expert on.

Re:It's Roland the Plogger, wrong as usual

[greg_barton]

Ya know, the whole Roland thing has been kicking around for a few years, and I'm starting forget why I was ever annoyed with him. I mean, really, how is what Roland does different from what Slashdot itself does? He's finding content and pointing it out to us. Slashdot does the same thing. He gets ad profit from hits. So does /. Big deal.

So, what is the big deal? Sure, someone did something similar last year. I'll clue you in to something: someone has always done something similar last year. It's called science. It's mostly evolutionary, not revolutionary. And do you really have to dis what the Purdue folks have done just because you're annoyed with Piquepaille? That's kinda petty, bubba.

Re:It's Roland the Plogger, wrong as usual

[Anonymous Coward]

Am I missing something?

Step 4

Re:It's Roland the Plogger, wrong as usual

[Ranger]

He used to link to his own blog article about it before rather than the actual story.

For once I wished I could have dugg this story down.

More efficient than fluorescents lights? Really?

[Anonymous Coward]

About two years ago I worked with someone who was in the LED industry, and when I said something similar (that LEDs produced light more efficiently than fluorescent bulbs) he stopped me and said that that was a popular misconception, or at least a statement that didn't tell the whole story. He later pointed me to a table showing various luminous efficacies at Wikipedia.

It turned out to be yet another experience where I'd heard something so many times -- something that just sounded right -- that I'd accepted it as being true. Kind of like the myth that flash memory's limited number of write cycles is something to worry about in real-world scenarios (it isn't).

At least the flash memory myth is dying though. It seems the majority of people are still championing LEDs as being at the top of the list of efficient light producers. Well they're not there yet, and for some lighting needs they'll likely never be.

LED lighting

[abigsmurf]

I look forward to lighting my house with an incredibly piercing, harsh light. LEDs don't do soft, natural light very well

Re:LED lighting

[Anonymous Coward]

I look forward to lighting my house with an incredibly piercing, harsh light. LEDs don't do soft, natural light very well

Well if you think the other alternative, compact flourescents do, you are on drugs. I don't care what anyone else says.

Re:LED lighting

[Eravau]

And so the gods of lighting invented globes and diffusers...a LONG time ago.

Re:LED lighting

[the eric conspiracy]

Which of course reduce efficiency.

To me light quality is the big knock against CF and LED. Both have some issues when compared with incandescent.

Re:LED lighting

[kesuki]

well, how about a luxim plasma light? http://www.treehugger.com/files/2008/04/luxim-plasma-lifi-light-bulb-led-cfl.php

considering that you could potentially replace streetlights with those bulbs, and they're the 2nd most energy efficient form of lighting that has produced at least a working example... nano crystal coated LEDs (the nano crystal coating is expensive though) are the theoretical #1, if only we had vast factories in space to produce the stuff for a mass market...

there is a shocking amount of research about lighting, what i like about this approach, is that it can theoretically be mass produced and here on earth. if only a few problems are solved first.. but researchers are predicting a 2 year turnaround until these silicon wafer LEDs are practical. so at least, we don't have long to wait to see if it catches on and if it does how much the price will be.

$100,00 - no way

[bvdbos]

I don't know about the USA, but if LED-lights cost about $100,00 over there I'm going to set up an export-company. They're like E 10,00 in the Netherlands. Of course, with the current exchange-rates that could well be $500,00 tomorrow.

Re:$100,00 - no way

[Anonymous Coward]

To be clear--$100 is the price point for current generation LED "lightbulb replacement" lamps. Most of these are lightbulb-shaped collections of many LED's, which screw into standard sockets and produce roughly similar light output to a "standard" lightbulb.

The price of the individual white LED's is of course substantially smaller.

Re:$100,00 - no way

[Anonymous Coward]

I think we're talking about two different LED lights. We have some that are roughly â15, See here but those are not a true replacement. The $100 ones are these ones that provide a much better lighting. If you have ones in the Neatherlands like that for â10, post a link. A few of us in the US would like to see that.

Re:$100,00 - no way

[bvdbos]

Yep, I have those in my home for this price (E10.00). Got them at the local shopping mall... Perhaps the presence of Philips in the Netherlands makes them cheaper over here?

Re:$100,00 - no way

[bvdbos]

I'm in no way connected to this store but these are the newest LED-bulbs from Philips: just one shop: modern.nl. I do have some connections with Philips so I can keep up with development.

Re:$100,00 - no way

[bvdbos]

of course, since this is Philips, the lights are rather expensive. There are cheaper brands with less quality. The intensity decreases much faster and there's paler colors.

Re:$100,00 - no way

[the eric conspiracy]

These are about 100 lumen bulbs. You would need about 15 of them to add up the output of a typical 60W incandescent.

Looks like you are still at $100.

Re:$100,00 - no way

[budgenator]

Don't see how, you could buy them wholesale at about E5.00, sell a case of 10 for E100.00, tack on E15.00 for shipping and handling, make us happy and make obscene profits saving the environment! If it were possible, somebody would be doing it already

Electricity savings ?

[Hektor_Troy]

I realise it's customary not to RTFA, but I would think that the submitters would at least read what they submit. Roland wrote:

It would also help to cut our electricity bill by about 10%

The article says:

a technology that could cut electricity consumption by 10 percent if widely adopted

Far from the same thing. But I suppose that's another reason people don't like Roland.

Re:Electricity savings ?

[Anonymous Coward]

Far from the same thing. But I suppose that's another reason people don't like Roland.

Wide adoption is a reasonable, implicit assumption when you're briefly summarizing the potential benefits of a new technology. Don't be such a pedantic whiner.

Re:Electricity savings ?

[Anonymous Coward]

Far from the same thing. But I suppose that's another reason people don't like Roland.

Nah. From my memory it's because he's a shameless selflink whore.

Re:Electricity savings ?

[Anonymous Coward]

forgive me, what's the difference?

Do LEDs blink ?

[dargaud]

Today for the first time I noticed a car with blinking tail lamps. When I say blinking, I mean it was blinking as fast as a CRT monitor, but the problem is that I can see it. I'm one of those people who has never been able to stand CRT monitors at less than 100 or 120Hz. I also have a hard time with some fluorescent lighting. I suspect what I saw was the lousy application of LEDs on the backside of a car.

So, suck it up, I hear you say. Right, except that each blink leaves an annoying remanent patch on my retina that lasts for a few seconds. Imagine driving at night in a city, 10 cars in your field of vision, look left, right and suddenly you have 200 spots in your field of vision. Awesome to know what's going on, right ?

I loathed the xenon high beams when they first came out a few years ago. You know, those tiny very concentrated blue lights ? Leaves a retina trail that lasts for 20 seconds. I'm so glad that they are gone now. I've never heard if they were made illegal or if they just went out of fashion, but I hope LEDs (which are a good technology) are applied in a good way...

Re:Do LEDs blink ?

[Anonymous Coward]

Short answer:

No.

Longer answer:

LEDs have a near instantaneous on-off time, in contrast with incandescents (which take a little while to warm up to/cool down from visible temperature--longer than the 60Hz cycle time on your household circuit). If you supply an LED with non-continuous current, it's going to flicker at the same rate as the current.

Re:Do LEDs blink ?

[eggnoglatte]

Well, given that car electronics are powered by a battery (i.e. a DC source), it would actually require extra electronics to make the light blink. My best guess is that you saw a car with a short in one of the wires of the electric system.

Note that in some LED applications, dimming is achieved by frequency modulation (i.e "blinking"). However, this is usually done at MUCH higher frequencies (several kHz), and I don't see why one would like to dim a car tail light.

Light fixtures in homes are slightly more tricky, because the power source is AC. You need an inverter and a small capacitator to suppress flicker, but that is pretty straightforward and inexpensive stuff, so there is really no reason why an LED bub should not contain these.

Re:Do LEDs blink ?

[funaho]

Are you referring to the effect where yuo see the light, look sharply left or right, and end up with a trail of dots in your visual field for a second or two? I get that a lot with brake lights these days.

I first noticed it a few years ago with the aircraft warning lights on antenna masts; it's only been the past 2 years or so where I've started noticing it on car brake lights as well.

Re:Do LEDs blink ?

[Destined Soul]

Actually, it is quite possible that dargaud saw frequency modulation. It is possible to over-power an LED but to pulse it such that the overall average is within the power limit. This is more of a guess on my part as I haven't played with overpowering LEDs much, but I would guess that the manufacturer had to power the LED so high (to get bright enough) that the frequency rate came within dargaud's visible range in order not to have the average power beyond the limit. I also wouldn't hold it to the maker to presume that anything above 60Hz is fine.

Odd about the dimming the light that way; IIRC the LEDs I've used can be extremely dim with low enough voltages without having to flicker it on/off.

Re:Do LEDs blink ?

[scorp1us]

Yes, the only way to vary the brightness reliably is to use PWM (Pulse width modulation, aka "duty cycle"). There is some variance from voltage, but the best way is to operate them at a constant voltage.

All "breathing" LEDS (like on sleep mode for laptops) is accomplished this way. Duty cycle is controlled by a simple sin() or cos() function.

Re:Do LEDs blink ?

[Anonymous Coward]

The blinking circuit is too allow different brightness levels such as the difference between braking and having the tail lights at night. It is much cheaper to simply use pulse width modulation with the already available ECU then it is to build a variable current analog circuit.

Re:Do LEDs blink ?

[toddestan]

I've always noticed a "twinkle" effect from the LED Christmas lights that usually blink at the line frequency, since they are too cheap to include a DC power supply. I wonder if someone might intentionally flicker the LED lights on their car in a similar fashion to get a similar effect and to grab people's attention.

Re:Do LEDs blink ?

[TaliesinWI]

I loathed the xenon high beams when they first came out a few years ago. You know, those tiny very concentrated blue lights ? Leaves a retina trail that lasts for 20 seconds. I'm so glad that they are gone now. I've never heard if they were made illegal or if they just went out of fashion [snip]

Xenon HID headlights never went away. They're still standard equipment on higher end Japanese and some German luxury cars and optional on many others. If anything, their use by car manufacturers are expanding, not contracting.

What YOU'RE complaining about, and thankfully seem to have gone away, are those high intensity blue color lights that dropped into a standard headlight assembly. Like you mention, I don't know if they were made illegal or became "uncool" but I hated them as well. True Xenon HIDs have a completely different reflector assembly than standard halogen headlights and spread the light far more evenly and are actually less annoying that a slightly misaimed halogen headlight, and you probably see them all the time and don't even realize it. They look "blue" only compared to what turns out to be the yellow tinge of a regular headlamp, but at a glance just appear very white.

Re:Do LEDs blink ?

[PPH]

I don't see why one would like to dim a car tail light.

You do this to replace dual filament bulbs used for tail/brake light functions. Its better to use all the LEDs (no holes in the pattern) even for the lower intensity mode, so they are dimmed using PWM (Pulse Width Modulation).

The visible flicker is a result of too low a switching frequency being used. Auto engineers would like to keep the PWM frequency away from audio frequencies, to keep interference out of audio systems. Its cheaper to use low ( 20kHz) frequencies.

Re:Do LEDs blink ?

[smellsofbikes]

My company designs LED driver chips. All our stuff is running in the very high kilohertz or low megahertz range -- far, far above where humans can see. All the drivers we've torn apart from our competitors are likewise quite high-frequency, usually 600 kHz - 1.2 MHz, but occasionally as low as 40 kHz.

LED drivers, if they're not just using a big power resistor, are all (that I know of) current-limited, chopping power supplies. It doesn't make *sense* to build those to run in the hertz range. I'm guessing whatever you saw was something broken, or in the process of breaking, and not the original designer's intent.

Re:Do LEDs blink ?

[NormalVisual]

I don't see why one would like to dim a car tail light.

It would allow you to use the same set of LEDs for both taillights and brake lights. Taillights would be dimmed, brake lights would be full power.

Re:Do LEDs blink ?

[NormalVisual]

Odd about the dimming the light that way; IIRC the LEDs I've used can be extremely dim with low enough voltages without having to flicker it on/off.

This is often true, but LEDs don't get brighter in a linear fashion when the input voltage (or current) is increased. Pulsing makes the perceived brightness much more controllable.

Re:Do LEDs blink ?

[Anonymous Coward]

It is probably nothing, but you might wanna go to a doctor and check your eye-pressure. I also see these long trails and after-images of lamps and lights. I always thought it was normal, but when checking my eyes, I had a bit elevated pressure. As long as my vision don't deteriorate it's ok, but now I go on regular check-ups. Later I heard about other persons with these after-images, also with elevated ocular pressure.

Re:Do LEDs blink ?

[Anonymous Coward]

At least here in central Europe, Xenon headlights are becoming more and more common -- however, it is now mandatory to have automatic regulators that tilt the lights downwards when the car is tail-heavy, so that you're hardly blinded any more. I still hate the blue edge to their light, because police cars, fire engines and ambulances are the only users of blue light in European traffic. It always makes you look...

The PWM of LED tail lights also affects me. I just hope that with time, manufacturers will use higher switching frequencies...

Re:Do LEDs blink ?

[Anonymous Coward]

Today for the first time I noticed a car with blinking tail lamps. When I say blinking, I mean it was blinking as fast as a CRT monitor, but the problem is that I can see it.

That would be very impressive. I would love to see how a human eye can see motion at 60Hz, especially since films are 24Hz and north american TV is at 30 Hz, and the human eye doesn't respond fast enough to see individual frames.

So, here are the possible explanations:

- you're a mutant
- you're lying
- the tail lamps were actually blinking and you are exaggerating the blink rate

So, suck it up, I hear you say. Right, except that each blink leaves an annoying remanent patch on my retina that lasts for a few seconds. Imagine driving at night in a city, 10 cars in your field of vision, look left, right and suddenly you have 200 spots in your field of vision. Awesome to know what's going on, right ?

Maybe you have some eye condition/disease and should get it looked at asap. At the very least, it sounds like your vision isn't good enough to drive.

Re:Do LEDs blink ?

[Anonymous Coward]

The pulse you are seeing is coming from the driver circuit. To get higher brightness, the LEDs are driven above their rated current. If the over current was constant the LEDs to dim and eventually fail. The circuit is quickly blinking the LEDs, lowering the duty-cycle and allowing the LEDs to cool. It's quite common where high brightness is needed, and several manufacturers rate their LEDs accordingly.

Re:Do LEDs blink ?

[Chrontius]

What you are seeing is the pulse-width-modulation dimming of the taillights applied with insufficiently high frequency. Cheap chinese flashlights like the Jetbeam C-LE (which has gone through three revisions prior to current - and is an absolutely excellent little LED torch) have been using increasingly high PWM frequencies to get around that; more expensive ones use current regulation (which averages the current of the PWM circuit over a few tenths of a second to produce a flat current (and therefore brightness) curve when viewed on an oscilloscope. The advantage of lower PWM frequencies is that the eye hands them off to the brain via a high-priority nerve link that results in people noticing them significantly (tenths of a second or so, IIRC) faster, theoretically reducing both the number and severity of accidents. The fact that many of them are bright enough to impair normal night vision seems to be lost on auto designers.

HID headlights have not gone away, but their implementations have been getting better - projecting beams on a down-angle so they don't nail people in the eyes, lowering the operating temperature of the bulb, making them less blue and more yellow-white without making them dimmer (actually, lower-temperature HID bulbs are more efficient than the blue-tinted ones). HIDs are popular for bulb life being insane, since headlight replacement was getting to be a significant drain in carmaker's warranty claims, and being brighter and having a longer effective range, which is good when there's no streetlights.

Entirely different is the blue-tinted halogen bulbs that are simply normal bulbs with a light blue paint applied - these are the ghetto-fabulous attempt to make it look like you've got an expensive HID conversion for an older car, and are about 30% dimmer than normal halogen headlights despite being harder on other drivers' eyes. I have no forgiveness for people who use these because they think it looks good.

Re:Do LEDs blink ?

[budgenator]

Obviously you haven't smoked a lot of marijuana or done LSD or you would have noticed it around 1969.

Re:Do LEDs blink ?

[novakreo]

That would be very impressive. I would love to see how a human eye can see motion at 60Hz, especially since films are 24Hz and north american TV is at 30 Hz, and the human eye doesn't respond fast enough to see individual frames.

Presumably the same way people notice a CRT flickering at 60Hz. It's not that uncommon.

Re:Do LEDs blink ?

[Anonymous Coward]

wow, you cant work anything below 100hz?

Re:Do LEDs blink ?

[Anonymous Coward]

The reason you're seeing the blinking is that the driver (sourcing the current) cannot power all the LEDs at once. So, the solution is to switch them very rapidly. You're in that low population of people that can see it. They just need to speed up how fast they switch or get a driver that can source more current so the end effect is minimal. Hell, you should become a lab rat for some design teams!

Re:Do LEDs blink ?

[Anonymous Coward]

Presumably the same way people notice a CRT flickering at 60Hz. It's not that uncommon.

Flicker is when the monitor's CRT is driven at a low refresh rate, allowing the screen's phosphors to lose their excitation (afterglow) between sweeps of the electron gun.

He said he "noticed a car with blinking tail lamps. When I say blinking, I mean it was blinking as fast as a CRT monitor"

Flicker & blinking are very different things.

Re:Do LEDs blink ?

[Anonymous Coward]

LEDs don't blink. They require DC voltage to operate properly. If you're ever played around with an electronics set that included LEDs (or diodes of any sort) you may have noticed that they are specifically marked with positive and negative terminals. They must have an appropriate potential drop (with the right polarity) to operate, so an AC supply won't work. The flicker you can occasionally catch in incandescent lights in the home is due to the 60Hz AC supply. Part of the expense in LED lighting in the home goes into converting the AC supply to a usable DC source. Oh, and IAAP (I am a physicist).

Re:Do LEDs blink ?

[Anonymous Coward]

I can see these blinking too. It drives me nuts and is very dangerous.

Re:Do LEDs blink ?

[giafly]

Everyone can detect rapid flickering if they keep their eyes moving quickly. My favourite technique is to eat something crunchy, e.g. potato crisps, so the vibration from my teeth slightly jiggles my eyes.

Re:Do LEDs blink ?

[zwarte piet]

The fast blinking might acually be a good thing for brake lights, but indeed annoying for regular tail lights. LED's don't run on 12Volts. They have a fixed voltage drop over them depending on the color, somewhere in the 1.6V to 3,5V range. So if you need to feed it of 12V you could use 3 or 4 of them in series and use a resistor. It would be hard making 20-40 LED shine equally bright this way. If you switch them all in series, you need about 40-100 volts or so to power it. That is easlily done with an oscillator and some diodes and capacitors. Of course 1 extra capacitor taking away the ripples, would solve the problem, but that would make it 15 cents more expensive. (or just faster switching of course)

Re:Do LEDs blink ?

[Ullteppe]

I just got a new vehicle with Xenon headlights, and I don't notice any blue tinge at all - perhaps this was just a problem with the early ones (I remember this a few years ago as well).

The difference in light is amazing - out in the countryside where I live Xenon headlights have just got to be a major safety feature - especially once winter season kicks in.

Re:Do LEDs blink ?

[Big_Breaker]

The supporting analog circuitry (caps, inductors, etc...) is much smaller and cheaper when switching frequency is increased. I'd be shocked if those car lights were running under 1kHz. Perhaps two similiar frequencies were being used and you were seeing a beating effect? Most likely it came from a facetted reflector with imperfect coverage strobing you with light and dark spots in the light cone.

Re:Do LEDs blink ?

[Big_Breaker]

24fps film works because the movie camera exposed the film for a large fraction of the 1/24 sec period. The action from that window is blurred onto one frame. This naturally happens on the human retina naturally and so when we view these blurred frames our brains can make sense of them without much fatigue at all. It seems like a much faster frame rate.

You'll notice in movies that the director will switch to high speed film. The openning scene of "Saving Private Ryan" is a well known example. It looks choppy. You can see individual specks of dirt being blown past the camera by the explosions. That's because the faster film allows the movie camera to hold the shutter open for a much shorter period. That means the "action" is caught for a much shorter part of the 1/24 second window. The shutter is faster but the film is still only 24fps. That means more detail and less bluring - so little bluring in fact that it looks choppy.

Re:Do LEDs blink ?

[zwarte piet]

I did some reading and it turns out that LED lights look much brighter to the eye if they blink at a certain frequency.

Re:Do LEDs blink ?

[Anonymous Coward]

so if the tail light was continuous you would cry about having an infinite number of spots in your field of vision?

Re:Do LEDs blink ?

[Anonymous Coward]

Some car designers decided it would be safer if they made the LED flicker visible, since it attracts the eye and increases reaction time in testing. Personally I think it was wrong, since it's very distracting it reduces my reaction time to other cars. I know there's a certain Cadillac model that has flicker on the order of 70 Hz.

Purdue University researchers?

[Fear the Clam]

Awesome. I wonder if these lights are powered by tabletop fusion?

many advantages

[drfireman]

LED light bulbs are coming along. I've been keeping my eye on the GeoBulb sold by C Crane, but it's about $120 and always seems to be listed as out of stock. It is available in three color temperatures, however, so perhaps that's been worked out. There are a few others, including some T8 replacements. Unfortunately, they're all expensive and the ones that fit standard sockets max out at about the equivalent of a 60 watt incandescent. But these things will get worked out. On the plus side, advantages include not just electrical savings and longevity, but also less heat (less risk of fire) and less vulnerability to things like vibration and moderate temperature changes. Unlike compact fluorescents, they contain no mercury and turn on/off instantly. I believe some are dimmable, but I'm not sure. In any case, it seems clear that it will only take a few years of fairly routine development for LED bulbs to be much more practical than all the alternatives. There doesn't seem to be a down side.

The summary would seem to imply only modest electrical savings. I'm pretty sure the 10% figure just reflects the fact that light bulbs are only part of your electrical picture. The rated wattage for a 60-watt equivalent is about 8 watts. Correcting for overoptimism, that's about 80% savings wherever you plug one of these in.

Re:many advantages

[smellsofbikes]

There are many, many LED drivers that are dimmable. Take a look at the National LM3405 or 3423: both accept a pwm signal for dimming, that can run from 10 Hz up to 200 kHz. (If it's under about 2kHz it's not a dimmer, though: it's a flasher, and it's really annoying.)

The trick is getting a replacement LED lightbulb, that fits in an existing socket, to work with an existing, cheap wall-mount dimmer. That'll be on the market within, uh... well, before mid-2009, certainly.

By the way, LED's have heat problems. In fact, that's probably their biggest drawback right now: they're flaming hot on the die itself. They don't *emit* any heat via radiation, but they dump vast quantities of heat through conduction. Current in-house LED replacement bulbs are the same size as an existing incandescent lightbulb, with this tiny little 2mm x 2mm die putting out the light, and the whole remainder of the volume being a big metal heatsink to try and soak all the heat out of that little die.

Re:many advantages

[drfireman]

The ones I've seen don't get hot, but then again they don't generate much light either. I don't understand the distinction you're making. Are you saying the bulb doesn't get hot, just the end that goes in the socket? I guess that's a decent alternative to having the exposed part of the bulb get hot. Aside from what's heated how much, how does it compare to incandescents in terms of the amount of heat generated? It seems like if you can get the same amount of light with less wattage, you shouldn't be able to generate as much heat, give or take.

Re:many advantages

[Anonymous Coward]

If the NEC electrical code would be updated, you'd have another advantage - currently a socket for an embedded light requires either an 8 inch diameter hole in your insulation, or a sealed box that is effectively a 5 inch hole in your insulation - both of which are due to heat from the light (and the wires carrying electricity to it). If LED lights could require a smaller hole, you'd have less heat loss on your top floor.

Re:many advantages

[smellsofbikes]

Okay, let's make sure we're speaking with the same terminology.
Hot things emit heat by three methods: conduction, convection, and radiation. That is: transfer by contact; transfer by heating some fluid that moves away from the hot source and heats other things; and by shooting out photons that are absorbed by other things, heating them up. Light *is* heat, although we generally look at heat as being the photons that are just slightly longer wavelength than what we can see.

Incandescents emit, depending on what sources you look at, something like 70% of the power they consume as radiated heat: they're blasting out *vast* quantities of infrared. Only a very small part of their total power use comes out as visible light. A hot object ejects photons over a wide frequency, as a boltzmann distribution (if I remember right.) So we see the tip of the iceberg, essentially, and all the rest is just heat. An incandescent does dump some heat through conduction -- something like 5% of its total usage, which is why light bulb sockets get hot.
An LED is almost exactly the opposite. It doesn't radiate *any* IR. (Well, that's not entirely true, but the IR that's coming off it is pretty small, and is because it's hot, about which more in a sec.) But it dumps something like 30-60% of its total drawn power through conduction. The die itself gets really hot, unless it is tied to a heatsink.

But, see, here's the thing: it's producing a *lot* more visible light per unit power consumed than a lightbulb is. So you can use an LED that draws very little power and still get lots of light out of it, meaning that the standard LEDs people have played with for years don't have any problem with heat because they draw so little power that they can dissipate all the heat they're generating even though they're encapsulated in plastic.

That's not the case with new so-called ultra-ultra-ultrabright LED's. (I kid you not: I've seen them advertised that way.) They're dumping out a *lot* of heat, so the die itself is bonded to an aluminum heatsink, which sometimes is sufficient, but in many cases the heatsink then has to be plated with something we can solder to on the back side, and that's bonded in turn to a bigger heatsink yet.

Take a look at these lights -- looks just like a CPU fan, doesn't it? Now in part those are intended to look awesome, but I can tell you, having worked with some very similar to that, they get uncomfortably warm if they're in any sort of enclosure, like a canlight mounted in the ceiling.

So to more or less answer your question: if you put the same amount of power through an incandescent and an LED, you're going to get similar amounts of heat produced. (The LED will produce less, but not an order of magnitude less.) However, you'll get many times more visible light out of the LED. For the same brightness, an LED will produce many times less heat. But you still have to get that heat out of the LED if you want it to live a long time.

Oh, and the other question: the 'bulb' is usually just a little bleb of epoxy on top of the die, to spread the light rather than just having it shoot out like a searchlight. If it does get hot, it does so only because the die is conducting heat into it, which is evidence of bad design (not enough heatsinking.)

Concerns about LEDs...

[MaWeiTao]

I've looked into LED lighting in the past and if it weren't so expensive I would have given some of these lights a try. So I look forward to the technology being more affordable.

However, a concern I have with LEDs is that the light is always too focused, even those that are supposedly less directional. This, in my opinion, makes them impractical to be used in the home. The light certainly is bright, but it's useless if it's casting only a narrow beam of light.

Perhaps reflective enclosures will address that issue. I suppose someone could cover an entire ceiling in LEDs, but I doubt that's going to fly for most people.

That reminds me of another thing... Can LED's be dimmed? As far as I've seen it's not possible. Some cars incorporate LEDs in taillights that in normal operation are dimmer than when the car is braking. However, that is achieved by flickering the lights which is far more noticeable than flickering fluorescent bulbs. Well, even CFLs have the same limitation.

Re:Concerns about LEDs...

[tftp]

Can LED's be dimmed? As far as I've seen it's not possible.

Not so. LEDs can be dimmed either by regulating the forward DC current (then they don't flicker at all) or by pulse-modulating some fixed current; the LEDs in the latter case will flicker only if the frequency of the pulses is too low. LEDs have very low capacitance and inductance, so they can be easily pulsed with any high frequency of your choice, though 1 kHz would be more than enough. And as I said the DC source works also.

Re:Concerns about LEDs...

[icegreentea]

Well, it could be possible to make LED bulbs out of a matrix of LEDs, and then have a controller which can turn off individual LEDs. Homemade LED ambient lighting systems already do this. You get a nice array of red blue and green LEDs, and using a controller you can change the colours being thrown on the wall. Cool stuff. However, I have a feeling that we may end up heading towards single element bulbs.

Re:Concerns about LEDs...

[toddestan]

In the context of replacing the bulbs in your home though, the answer may be slightly different, as dimmers on light fixtures intended to power incandescant bulbs aren't going to work properly with the LED bulbs. However, it should only be a matter of replacing the dimmer switches to get them to work.

Re:Concerns about LEDs...

[mark-t]

You can dim an LED by rapidly turning the LED on and off, and changing the percentage of time the LED is off. Theoretically, all of the electronics necessary to convert an analog voltage level into a modulating digital signal necessary to simulate a dimmer could be built right into the base of the bulb, so that existing analog dimmer switches could still work.

Re:Concerns about LEDs...

[mark-t]

It depends on how the LED bulb is designed. As I mention elsewhere, the electronics to convert the voltage level into a digital signal with a varying duty cycle based on the level of the analog signal is trivial enough that it could easily fit inside the base of a bulb to work with ordinary dimmer switches.

Re:Concerns about LEDs...

[Mr. Flibble]

Dimming LED's.

LED's are commonly dimmed in headlamps. I have right next to me a Petzel Tikka XP Headlamp that has multiple LED light settings. And yes, each of those settings is a different dim setting. The LED can also be "over-driven" for a short period, putting out more light than normal.

So, parent poster is correct, LED's do dim, and they dim quite well.

Re:Concerns about LEDs...

[CosaNostra Pizza Inc]

LOL. Couldn't you just use a Potentiometer as a "dimmer" and limit the current? LEDs usually need current limiting resistors anyway.

Re:Concerns about LEDs...

[mr_walrus]

household lamp dimmers do not vary voltage, they use a cheesy triac circuit
to chop the AC current. not much different in concept than PWM for leds.

Re:THANK GOD

[Anonymous Coward]

At least the jews don't want my girlfriend to wear a rag on her goddamn head.

There is already better lighting tech

[scorp1us]

There is a company working on a replacement righting technology. It is 2x as efficient than LED, and has a much better frequency profile that matches natural light.

It is a capsule of gas, which is surrounded by a oscillating field. This field causes the gas to emit photons. (My dad used to have a neon capsule that you could put next to a AC current and see if there was current flowing - same principle)

LED is on its way out already.

Re:There is already better lighting tech

[duggy_92127]

To paraphrase the internet as a whole: "Links, or it didn't happen."

Doug

Re:There is already better lighting tech

[funaho]

Oh yeah I remember reading about those a few months back...the neat thing is they don't require any electrical contact with the fixture.

Re:There is already better lighting tech

[Anonymous Coward]

Oh yeah I remember reading about those a few months back...the neat thing is they don't require any electrical contact with the fixture.

Other than the "2x as efficient as LED" thing, parent and grandparent have described a fluorescent bulb. Having the electrodes in contact with the gas increases the efficiency a bit, but increases failure rates of the bulbs. It's a compromise that favors the bulb makers. Go figure.

Re:There is already better lighting tech

[funaho]

This was not a standard fluorescent bulb. The gas inside the capsule radiated visible light directly (no phosphor coating), and it was BRIGHT. It took me a few minutes but I finally found an article about it here

So what about

[Anonymous Coward]

1) Motion lamps? ie Lava lamps? 2) Oven lights? 3) Fridge lights? OK, LEDs will probably work a lot better than CFLs in the cold, but is the color balance going to be the same as an incandescent? 4) Bread ovens where lamps are used to heat? 5) Toy ovens with a lightbulb?

So, which is more efficient again?

[plasmacutter]

only 10%?

I replaced all the bulbs in my house with CFL, and I like my lights bright.

75 watt bulbs were replaced with 25 watt.. .

that's a cut in electricity use of 66% with CFL's.

Re:So, which is more efficient again?

[Anonymous Coward]

only 10%?

I replaced all the bulbs in my house with CFL, and I like my lights bright.

75 watt bulbs were replaced with 25 watt.. .

that's a cut in electricity use of 66% with CFL's.

So you don't have a computer, refrigerator, dishwasher, television, or any other electricity using applainces?

Or have you just decided to compare two totally different things? Because a 10% cut in the total amount of electricity used in a house is going to include all the non-lighting electicity usage, while you seem to be assuming that lighting is the only electric thing in the house.

Re:So, which is more efficient again?

[Daniel_Staal]

I think CFLs are marginally more efficient, but they contain trace amounts of mercury and so should be given special handling in the trash. LEDs have no toxic materials, last longer, and are very close efficiency wise. (They are also currently much more expensive to produce, and have a narrower color range.)

Both groups are trying like mad to fix their downsides first. CFLs are ahead because their costs are already low.

Re:So, which is more efficient again?

[RoboRay]

He uses gas for everything other than lighting. Well, his ancient 386-based computer burns coal, but everything else is gas.

Re:So, which is more efficient again?

[plasmacutter]

close... I use steam engines, none of that new fangled "gaslight" stuff.

now where is my buggy whip.. i need to go out for some takeout.

Supporting evidence?

[illegalcortex]

I don't really expect to see any of these things. I've done some shopping today and see that you can ALREADY buy replacements for tail lights that screw into the same socket as the incandescent bulbs for far cheaper than your projected expected $1000+. Doing some very cursory googling, I see you can get a pair of really nice looking truck ones for $300. So that's $150 per tail light. You can also put "LED tail lights" into amazon and find plenty for $20-$50 a pair. That's the entire light, not just a single bulb.

The only place I can see it costing significantly more is for luxury cars like BMW/Lexus/etc. And that's only because everything always cost a premium on those cars.

Your expectations of home builders seem equally implausible. Do you even realize how often the home builder themselves would accidentally break the lights? They're not going to buy products that cost them $1000 when someone slips up and hits the bulb with a hammer. Equally unlikely is the success of any light fixture with a non-replaceable bulb sold directly to consumers. One of the first things they'll notice is that they can't replace the bulb. They'll either not buy it in the first place, or take it back and get a refund.

All in all, I just find your expectations to conflict with what I know of reality.

Forget Compact Flourescent

[lawpoop]

I'm as much of a tree-hugger as the next guy, but I really don't like Compact Flourescent bulbs. Theoretically, if you're worried about energy use, they're a good idea. But I think in practically, they're a bad idea, because of the mercury content.

Compact fluorescents give out crappy light, and nobody really wants crappy light in their home. It's the wrong color, wrong intensity, etc. Once LEDs become widely available, we'll all be throwing out the compacts, and replacing them with LEDs that give off light that we like. Those compacts have mercury in them, and all that mercury will be going straight into the landfills and our drinking water. The compacts have a life of 10 or so years; but we won't be using them that long, once LEDs come along. So the long-term money saving aspect will be a waste.
Also, I can't count the number of lamps and light-bulbs I smashed as a kid. Do you want your little ones smashing up these compacts and getting a good dose of mercury vapors?

I say just hold off until LEDs really become affordable. Don't put any more mercury into our environment; especially not your home.

Re:Forget Compact Flourescent

[Anonymous Coward]

So in summary, keep buying wasteful incandescents for the next five to ten years because its too much of a hassle to recycle CFLs, or the bother to find one you like.

Re:Forget Compact Flourescent

[greyhueofdoubt]

>>Once LEDs become widely available, we'll all be throwing out the compacts, and replacing them with LEDs that give off light that we like

Er... I don't know anyone who threw out perfectly working incandescent bulbs just to install CFLs. That would be a ridiculous waste of a good bulb. The people who hate CFLs enough that they would throw out a working CFL bulb in order to buy a very expensive LED light would, I assume, either be insane or else they simply wouldn't have bought the CFLs in the first place.

I mean, look at the initial cost + operating cost for these things.
CFL- $3.50 + power cost, let's say... $100 over the (long) life of the bulb
LED- $120 + power cost, let's say... $50 to be very generous.

Even if the power cost for the LEDs was zero, they still cost more than CFLs unless you use them for decades. I myself have been replacing bulbs on an attrition basis and will continue doing that in 10 years when my CFLs burn out, break, or I decide to move into a van down by the river.

-b

Re:LED = Luxury Goods^H^H^H directional and color

[claykarmel]

I don't think so.

Trucks and cars use LED lighting for the same reasons that traffic lights do. They are already colored and directional.

Low heat, low power dissipation and high shock/vibration tolerance are also pluses.

LED home lighting can avoid the CFL problem of being 'too white', and may first appear as architectural lighting (where intensity and color are varied by time of day, event or spacially).

I know I'd pay more for a LED solution that wasn't 'cold white', rather than install florescent in my kitchen or bathroom. Building codes now require florescent in those rooms, so look there for early adoption in new homes (when the present housing crisis abates).

LED already cost-effective in some situations

[rickkas7]

LED lighting is already cost effective in certain situations. I priced a cable-hung low-voltage lighting system using LED-based MR-16 socket bulbs vs. 12 volt halogen incandescent and the system pays back in less than a year in electricity savings. That doesn't even count the significantly smaller number of bulb changes that are required.

If you have a large number of low wattage/low voltage light sources, CFL is not viable, but LED is. The power requirements are so much lower that smaller transformers can be spec'd, you can string piles more of them on a circuit, saving even more money.

There are some neat bulbs available at http://www.theledlight.com.

CFL Color

[wooferhound]

you need to look at the Color Temperature when you buy CFL bulbs. A CFL rated at 2700 degrees Color Temperature will look almost exactly like an incandescent light. A CT of 3000 degrees is called a warm white and is very pleasing. A CT of 4000 is called a cool white and looks a little bit blue. And a CT of 5000 degrees or more is about the same color as Sunlight and appears to be very blue indoors.

I really like the color you get when a 2700 & 5000 degree light are in the same fixture, everything looks bright and colorful.

Re:CFL Color

[Hatta]

Sunlight is slightly yellow, so why does a daylight CFL look blue?

Re:CFL Color

[Cyberax]

Perceptions.

Direct unfiltered sunlight indoors doesn't look yellow, it's almost pure white.

Sun's spectrum is very close to the ideal black-body spectrum with the color temperature is about 5000K. So 5000K CFL will look almost exactly like the real sunlight.

Re:CFL Color

[Waffle Iron]

I think you have sampling bias. The sun looks yellowish at the only times of the day that most people can stand to even glance at it: the morning and evening. That's because it's filtered through lots of dust in the atmosphere. Look at a sheet of paper in the sunlight at high noon on a clear day. It won't look yellow at all.

Re:CFL Color

[ivan256]

Not perceptions... Quanta

Look at the sun and at a CFL though a spectroscope. With the sun, you'll see even intensity across the spectrum. When you look at the CFL, you'll see several distinct bars of light at specific wavelengths. While both average out to about the same color temperature, the sun will have a black-body spectrum, evenly illuminating the pigments in the items in your room, while the CFL will make certain colors in the room jump out more than others.

Re:CFL Color

[ivan256]

Here's some links:

A white LED's spectrum

A CFL's spectrum

Re:CFL Color

[ArtemaOne]

The light from the sun is mostly green. The atmosphere scatters a bit of the blue giving a perception of yellow due to the contrast. If you actually measured the colors with a device it wouldn't be yellow.

Re:CFL Color

[kklein]

God bless you. Proof positive that CFLs do, in fact, look like shit. I ought to put that second one in my sig.

Re:CFL Color

[Chrontius]

That is a very wide-band white LED. Wikipedia has a better look at it here.

Re:CFL Color

[Alioth]

My LED bike light is something like 5000K. When you first turn it on, it looks very pale violet rather than white (like most "white" LEDs). But after a couple of minutes you are used to it. Since I cycle on unlit roads, whenever a car comes by with normal halogen headlights, its headlights look as orange as low pressure sodium lights. But I'm sure the car's driver sees the same light as white (and see my headlight as pale violet).

Re:CFL Color

[somersault]

That's entirely up to personal preference. I much prefer bluer 'cool' colour calibration and fairly high contrast in my monitors to 'warm' yellowy nonsense, and the same goes for things like lightbulbs. I don't mind yellowish sunlight, but that is because it brings warmth and often better visible definition than the pale light you get on dull cloudy days. You also get nice blue skies to balance out the yellow.

Since it's summer here at the moment (bright enough from around 4am-11pm) I don't often need to use artificial lights anyway :) When winter wraps round I'll probably still get by with the light from my TV most of the time as well ;)

Re:CFL Color

[Anonymous Coward]

If you read the article, you'll see that the device used on the LED spectrum is different and smears it out. White LEDs are florescent (blue LED + yellow dye).

Re:CFL Color

[kklein]

How is this a troll???

Oh, right... I made reasoned arguments against Linux in another thread and now someone's gone through and modded all my shit down... It's been awhile...

Link

[scorp1us]

Luxim Plasma

Re:Link

[iivel]

If I had any mod points left, I'd mod this up....very cool. First I've seen of it. Any idea what the bulb operating temp is? I've used metal-halide systems in my aquariums for years and they get HOT.

Re:Link

[scorp1us]

Video (in link) says 6000K at the center. But - that is for a 250w bulb. There may be some issue of having to maintain the temperature for the plasma, in that case, perhaps we can have a central, hot lighting boxthen use fiber to move the light around the area to be lit.

Re:Link

[iivel]

I'd assume that to be the color temperature though right? 6000K would be awefully hot for something on earth no?

What about SMD bulbs?

[asc99c]

I'm getting some SMD bulbs which produce very nice quality light. Normal LEDs are packaged to intentionally direct the beam, as this has generally been desirable for most applications so far. But this isn't necessary.

LEDs don't inherently produce highly directed light, and hopefully we will see more of these SMD bulbs in future.

Here's the one I've got - it's a spotlight bulb because that's what the light fitting takes, but there are standard bulbs also available.

http://www.globalgreen.co.uk/led1.php

LEDs are not actually effiicient yet

[Anonymous Coward]

For the record, white LEDs in real-world conditions are not yet as efficient as fluorescent lighting, and indeed in nice warm white colours (rather than very cold white) are only just getting better than low voltage halogen.
The figures that the manufacturers quote are correct for a 25C junction tempearature. While this, as I understand it, is the standard for electronic specifications, it isn't realistic in the real world as the heat generated by the LED tends to heat it to a junction temperature of at least 80C, even with good heatsinking. The tests are carried out either in refrigerated lab conditions, or by a 25ms pulse of current which doesn't give the chip time to heat up.

White LEDs may well become useful in the future - but not yet.

My money is on OLEDS

[Bender_]

OLEDS have made surprising progress recently in term of efficiency. They are especially interesting because they offer completely new form factors like 'lighting tiles'.

http://www.eetimes.com/showArticle.jhtml?articleID=209100587

Can you buy LED lightbulbs anywhere NOW?

[Anonymous Coward]

I hear they are expensive, but I thought they were already commonplace. I thought everyone knew that CFL bulbs were garbage. I've gone to Home Depot, Target, Wal-Mart, and I still have not been able to find LED lightbulbs. I don't care about the price. Where can I get one?

Ridiculous article, again

[Ancient_Hacker]

Perhaps somebody should look at the efficiency claims. LED's are somewhat more efficient than incandescent bulbs, but far far less than fluorescents.

That is why every laptop has two or more fluorescent bulbs, and no LEDs to light up the display.

And the economic claims are ludicrous. Nothing has ever come out at a far lower price than what it replaces. The greed of the marketplace will ensure just enough middlemen, distributors, jobbers, and salesmen to bring up the price to just a bit under the competition.

Re:Ridiculous article, again

[cnettel]

Eh, have you been hiding under a rock during the last year or so when Sony, Apple and many other manufacturers have started offering laptop LCDs with LED backlighting, stating that they give a better color gamut, that they are thinner, and that they are more power-efficient (although this is usually traded off for a brighter maximum setting)?

I bought two $30ish LEDs - they suck

[Maxo-Texas]

Very dim. About 50% of the amount of light they advertised to put out.

Even adding a lot of these wouldn't increase the light above "dismal" level-- the intensity of the light was just lower than that put out by CFL and incandescent.

I want LED to work-- they last a long time, they use no power, and they have no mercury.

These might be okay for a porch light-- dim but always on.

Re:I bought two $30ish LEDs - they suck

[asc99c]

In fairness that's the main thing I've seen them advertised as. At 1W of power, you can leave them on 24x7x365 for £1 / year - with US energy prices that would probably be $1 / year I guess.

This is very useful for highlight lighting - I've got a glass fronted cabinet that looks great lit up but I can't justify using 80W of power for the incandescent bulbs just for decoration.

Also, they are incredibly efficient at very low luminosity, where incandescents and CFLs are terrible. My brother is setting up a cinema room in the attic and using low power LEDs as background lighting.

Re:I bought two $30ish LEDs - they suck

[evilviper]

I want LED to work-- they last a long time, they use no power, and they have no mercury.

I would be interested to hear you explain your opposition to florescent lighting. They are much more energy efficient than existing LEDs (and have been for DECADES), and contains a very tiny amount of mercury. LEDs aren't exactly free of toxic chemicals.

Re:I bought two $30ish LEDs - they suck

[Maxo-Texas]

Are you talking about classic 24" to 36" long tubes? The light from them is pretty bad.

The modern CFL's draw 13 to 17 watts. The LED draws about 2 watts for half the light. So 4 watts for the same light.
They look good for about a year and then, the 75 watt bulb produces less light-- say 60? Then it slowly declines over the next 5 years.

I use CFL's but I mix in some incandescent.

Re:I bought two $30ish LEDs - they suck

[evilviper]

Are you talking about classic 24" to 36" long tubes? The light from them is pretty bad.

Well, no. CFLs have been around for a LONG TIME. I had a set a good 20 years ago... The only thing that's changed, recently, is that the ballasts are dirt cheap, so we just throw them away, rather than swapping the bulb.

Still, there's nothing wrong with long tubes. It's exactly the same tech. No doubt you're basing your judgment on very old tube setups, versus new CFLs.

The modern CFL's draw 13 to 17 watts. The LED draws about 2 watts for half the light. So 4 watts for the same light.

I haven't got any idea what you're talking about. There isn't any LED tech in the world that is even AS efficient as CFLs right now. It's merely hoped that they will get there soon.

Re:I bought two $30ish LEDs - they suck

[Maxo-Texas]

Sorry dude, the light from florescent sucks compared to incandescent.
Most of my friends feel the same.

If CFL works for you- more power to you.

CFL bulbs are only full power for about 12-15 months- for the rest of their lifespan, they put out less light.

Hopefully GE will get the new incandescents that are more efficient on line. Hopefully they will get LED's working- because the quality is decent but too weak.

Re:I bought two $30ish LEDs - they suck

[evilviper]

Sorry dude, the light from florescent sucks compared to incandescent.
Most of my friends feel the same.

The plural of "anecdote" is *not* "evidence". Sorry. I don't care how many of your friends believe the world is flat.

I would suggest that you and your friends go find some good ones, rather than the latest Wal-mart specials...

CFL bulbs are only full power for about 12-15 months- for the rest of their lifespan, they put out less light.

No. Nobody puts a 12-month timer in them... Florescent bulbs are only "full power" for about the first second you turn them on. After that, it's a very slow (and entirely linear) decline.

And guess what? LED arrays have a similar decrease in output over their lifetime as well. Incandescents do as well, for that matter.

Re:I bought two $30ish LEDs - they suck

[Maxo-Texas]

If you tell me the sky is black, and I look out the window and it's blue and my friends agree it is blue then it is anecdotal but you are not going to convince me.

Perhaps you are on the other side of the world where it is indeed black.
Perhaps you are buying $9 CFL's instead of $5.

Perhaps the drop in lumen output doesn't bother you-- I have a friend who can see the difference between 60hz and 50hz-- I can't. It's been related to me anecdotally that a friend who was getting an EKG was shown that his brain reacted to incandescent light once but reacted to every pulse of the florescent lights.

New CFL's are bright enough that they bother my eyes a bit when I look at them. I have other CFL's under 2 years old that I can look at and see they look dim.

I use 5 light fixtures and what works for me is 4CFL's (one cool, three warm) and an incandescent.

It's not like I don't use CFLs when I say that they have serious performance issues from experience.

I think they must be cheating slightly on the lumen ratings because the total light in the room is just lower for a 60w cfl vs a 60w incandescent. I have to go to 75w cfls to feel the same about the light levels (and that's about 22w so it's still a great savings).

Anyway.. this is getting old- take a last reply if you want and i'm going to move on.

Enjoy your LED lights now,

[LM741N]

because they aren't going to exist much longer into the future. http://www.idtechex.com/products/en/articles/00000591.asp

I also find it ironic that everyone seems to love that mercury is not contained in LED's, yet is it essential to the extraction of gallium from ore.

$100 to $5?

[Flentil]

According to the blurb, current LED bulbs sell for $100 and they expect this new breakthrough to lower the cost to $5. I can see that being possible for the manufacturing cost, but the cost to the consumer will always be set to one click below 'haha yeah right'. It's the way of business. Look at how many times in the past couple years we've been told that the cost to manufacture solar panels will be cut in half. You'd think with all that progress we'd be able to roof a house with them for about $10, when actually the cost remains one click below 'are you insane?' as always.

Spectrum is an issue

[davidwr]

I don't like LEDs for room lighting the same reason I don't like most fluorescents - the spectrum just isn't there.

Give me a white light that either covers the same spectrum as a typical incandescent or at least come close enough that I don't notice the difference, then I'll consider it as a drop-in replacement for standard bulbs.

Oh, and of course be cost-effective in the long run, environmentally friendly/easy disposal, etc. etc.

gatekeepers: Underwriters Laboratories and FCC

[Anonymous Coward]

The number one concern has not been mentioned yet at all: government regulation. In many parts of the US, anything electrical that is permanently attched to a house must be certified by Underwriters Laboratories. Unless you have decades of experience, then UL does not certify anything whose failure modes include fire. DC current regulation is prone to fail by short circuit and fire. Pulse modulation requires shaping because the FCC allows no radiation at 10 KHz (ten kilohertz) or greater, and the obvious circuits all have harmonics that intrude.

negatives of flourescent lighting

[CosaNostra Pizza Inc]

*They don't last as long when switching on/off for short periods of time *From my own personal experience, they do not last long at all in humid environments (ex: bathroom lighting)

Woohooo!!!!

[NerveGas]

10%! Excellent!

That way, I can spend money to replace all of my light bulbs, and throw away all of the fluorescents that I spent money on...

all to save less money than if I just turned my lights out more often.

Build me an LED screen!

[Dr. Spork]

I know we've been promised OLED displays, but if solid-state blue LEDs are going to be cheap, I want them to make a screen from them. (I know green and red are absurdly cheap; the blue ones were holding this back.) I'm sure they could make them much smaller, but suppose you had a 3-diode pixel that was 5mm across. A high-definition display made from these would be almost ten meters wide, which would be awesome in movie theater, a stadium or an outdoor display. Plus, it should be pretty simple to yank out and replace any pixel that burns out. These would be incredibly power-efficient, because they would use no power at all to display black. Basically, you could use them for super-efficient, programmable room lighting as well - and how cool would that be?

Re:Build me an LED screen!

[icegreentea]

LED displays already exist. Fremont Street Experience in Las Vegas (giant canopy display) is a giant LED screen. Some of the modular large screens are also built this way. Many stadiums are also already using LEDs for certain displays. As for programmable room lighting, go check instructables. They have a bunch of projects there (I plan on building one myself in the near future). If you use the right controller, you can auto sync your room lighting to whatever music is playing and the like. Cool stuff.

Just a different toxic soup

[EmbeddedJanitor]

... used in their manufacture.

Unbroken florescent tubes can be collected and safely disposed of.

Incandescent bulb heat

[Anonymous Coward]

I've wondered how incandescent bulb heat compares in efficiency to radiators and such. Would it make sense to switch to incandescent in the winter and use CFLs (or LEDs) in the summer?

Indoor greenhouse

[malkir]

The most exciting part of all about this for me is the possibility of low-cost indoor growing systems. NASA is currently using LED's to grow cabbage and tomatoes in space - I've seen several successful applications for growing 'tomatoes' indoor as well. The advantages to indoor LED growing is less heat produced, less electricity used, and you don't have to shovel out money on HID lamps with a ballast. As soon as the prices of LED's go down you can expect to find a lot of dank on the market!

10% of electricity into light?

[Anonymous Coward]

Most incandescent bulbs are only 2 to 3% efficient!

Why does efficiency matter, except in summer?

[TwoAtHiOne]

The rest of the year, the incandescence bulb is helping to heat my house. Is the light bulb that much less efficient at heating my house than an electric heater?

Re:Why does efficiency matter, except in summer?

[Ken_g6]

Is the light bulb that much less efficient at heating my house than an electric heater?

That depends. Light bulbs are ~95% efficient as heaters. That's similar to electric resistance heaters. But it's much less efficient than a heat pump.

As compared to simple heaters, heat pumps have efficiencies of 175-600% by getting heat from a place that maintains a constant temperature. (They pull heat out, but more heat migrates in to take its place, so that's essentially free heat.)

Natural gas furnaces also tend to be more efficient - 80-97% efficient. That may not sound like much; but if the electricity to run your light bulb was made from natural gas, that process was only 60% efficient at best.

Wrong on so many counts....

[brunes69]

• RE mercury - the CFL mercury myth / paranoia was debunked long ago. A CFL bulb in it has 100 times less mercury in it than a watch battery, and . Are you concerned about your watch battery? What about your thermometer in your medicine cabinet - the one with 500 times more mercury in it? You know what the recommended disposal procedure is for a CFL as specified by Environment Canada? Wipe area with a damp paper towel. Oohh.... that is scary stuff!

  In addition to all this, it is estimated that for every CFL you use you save about 10 times the amount of mercury in the atmosphere, since most power in North America still comes from coal, and burning coal emits a lot of mercury.

• RE light quality - the light quality issue with CFLs was solved years ago. You can now get CFLs with any light temperature you want, going all the way from "cool" (more like white, natural light) to "warm" (more like incandescent light, which actually is very different from natural light). This leads into the third gripe...
• The idea that LED light will be more like incandescent light is total baloney. LED light is almost pure white, it is nothing like incandescent at all. So if you don't like CFLs because you feel they are not like incandescent, then you sure as hell are not going to like LED bulbs.

Re:Wrong on so many counts....

[lawpoop]

You are right about reduced mercury from coal plant emissions ( but that's all the more reason to go solar/wind , but the US EPA says to do this if you break a CFL:

• Clear the room of people and pets
• Open a window and shut off any heating and air conditioning
• Dispose of any fabrics ( clothes, bedclothes, etc ) that may have come into contact with the bulb or mercury.

I know that the US EPA has had a less than stellar record under the Bush administration, but why are they so much more paranoid about mercury in CFLs than Environment Canada?

Re:Wrong on so many counts....

[FeatureBug]

No, that is misinformation. Medical consensus is that exposure to mercury from broken fluorescent tubes, even after attempted cleanup (wiping or vacuuming removes relatively very little mercury, primarily because many mercury binds to, or for porous surfaces, penetrates deeply into many types of surfaces), is damaging to health and capable of causing symptoms of mercury poisoning. This has been known since at least Tunnessen WW, McMahon KJ, and Baser M (1987). Acrodynia: Exposure to mercury from fluorescent light bulbs. Pediatrics 79(5):786?9. PMID 3575038

Secondly, in the last 5 years, mercury pollution from coal-burning power stations increased significantly because the amount of coal burned has increased by over 15% due to rising electricity demand, this despite sales and use of CFLs having increased significantly (CFLs make only a small difference to total electricity demand).

LED lights

[falconwolf]

But how much of an improvement will they be over fluorescent lights

Unfortunately what TFA doesn't say is that currently LEDs are only good for spot lighting and not area lighting. In other words they can be used to read a book but not light an entire room. While LED lights for areas are available they are more expensive than other LEDs, which are themselves expensive.

Falcon

LEDs and CFLs

[falconwolf]

they won't flicker

My CFLs don't flicker either. I've been buying CFLs for more than 10 years and I never had one that did flicker.

they won't contain mercury

True but coal fired power plants emit more mercury to produce the electricity to power incandescent lights than CFLs contain. On top of that, I wonder what alphabet soup of toxins are created in the manufacturing of LEDs? And how does that compare to the manufacture of CFLs?

Falcon

I tried white LEDs

[Ivlis]

I tried white LEDs. They output 50% of the light of incandescent bulbs for the same electricity.

The manufacturer claimed energy savings, but that was comparing bright incandescent bulbs to dim LEDs.

Rooms with people get lit while others don't.

[falconwolf]

That can already be done. You can buy a motion detection switch or lights with built in motion detectors at Home Depot.

Falcon

Re:Rooms with people get lit while others don't.

[james_orr]

Yeah, I used to work at a place where the only way the light went on/off in the bathroom was a motion sensor. Sitting on the toilet you had to wave your arms around every now and then or be plunged into darkness.

Re:Rooms with people get lit while others don't.

[CByrd17]

Plunged! Hahahah!

Re:Rooms with people get lit while others don't.

[falconwolf]

Yeah, I used to work at a place where the only way the light went on/off in the bathroom was a motion sensor. Sitting on the toilet you had to wave your arms around every now and then or be plunged into darkness.

I' say the placement of the motion sensor(s) were bad. I had the same problem at an apartment I lived in, the light for the patio was on a motion sensor. I smoke but not inside, so I'd step out to the patio to light up. I always bring something to read but at night the light frequently turned off. On the other hand the lights would turn on when deer went by, which was frequently while I lived there, between fall and spring.

Falcon

CFLs

[falconwolf]

I think it's over 5 years since my parents and myself use only CFL and none broke.

I bought my first CFL about 20 years ago, it cost more than $20, and I've only bought CFL light bulbs since except for flashlights and I have yet to have one break. On the other hand, it's possible to drop one when changing bulbs. What I do is hold the light shade or dome under the bulb so if it does drop it will be caught.

Falcon

Re:CFLs

[TheLink]

"and almost all the bad ones were made in China"

Were almost all the good ones were made in China too? ;)

Re:CFLs

[Lodragandraoidh]

I have an early model CFL in my garage that has been going strong for 6+ years. In that same span of time, I can't recall how many times I've had to change the incandescent bulb over the front porch. The early style bulbs had 4 tubes that projected straight out - they were not at all shaped like a light bulb - like the newer ones today that corkscrew to create a 'light bulb' outline - hence why I couldn't fit one inside of my porch light fixture globe.

All the replacement bulbs I have now are CFLs, and as the incandescent bulbs die out, they are being replaced by CFLs.

As far as the quality of the light emitted - I can't tell the difference between an incandescent and a modern CFL - the CFLs in my house are not at all the same as the florescent bulbs in my office building - which seems to produce a greenish light - though it doesn't bother me as much since we moved to LCD screens; for some reason the old CRT screen refresh rates would interact with the florescent vibrations to cause noticeable flickering.

Re:CFLs

[falconwolf]

"and almost all the bad ones were made in China"

Were almost all the good ones were made in China too? ;)

No, actually the better ones were made either in the US or in Europe according to the report.

Falcon

Re:CFLs

[falconwolf]

The early style bulbs had 4 tubes that projected straight out - they were not at all shaped like a light bulb - like the newer ones today that corkscrew to create a 'light bulb' outline - hence why I couldn't fit one inside of my porch light fixture globe.

I've bought the ones with straight bars sticking out, ones with two "U" shaped bulbs, and the cork screw bulbs. The old straight bar ones didn't fit many fixtures but the cork screw bulbs are about the same size as the incandescent bulbs they replaced. The ones I got are 12 watt though and the 15 watt bulbs probably won't fit.

All the replacement bulbs I have now are CFLs, and as the incandescent bulbs die out, they are being replaced by CFLs.

That's what I did, as the incandescent bulbs burnt out I replaced them with CFLs. I recommend this over simply replacing good, well still working, incandescent bulbs. Buy one or two CFLs then when an old bulb burns out replae it with a CFL then buy another CFL. With the drop in prices, and the wider availability of CFLs, it doesn't matter much any more but it allows people to evaluate the bulbs. If one isn't good they know not to get anymore of them.

Falcon

CFL colour temperature

[falconwolf]

They appear the same except the CFLs are brighter and their light isn't as yellow.

Actually it depends on the light bulb as to what colour is emitted. Different CFLs have different colour temperatures, some emit yellow light, some emit blue light, and some emit a more balanced light, day lighting.

Falcon

dental fillings

[falconwolf]

That's all well and good but you would be surprised at how much mercury gets into the environment from dental fillings and how few people will pay the extra $15.00 to get composite fillings!

Not everyone knows dental fillings contain mercury. I got into an argument with someone over that, I had to prove to them mercury was used. And not all dentists use composite fillings.

Falcon

dimmable CFLs

[falconwolf]

you can't put fluorescent lighting on a dimmer

CFLs can be used with dimmers, there are dimmable CFLs.

Falcon

CFLs

[falconwolf]

I've got two of the "high quality" CFLs over my head as we speak. They have 95+ CRI and give everything in the room a very accurate color cast. But if it wasn't for a couple incandescent bulbs next to them I'd have vertigo and a throbbing headache.

All I have over my head is CFLs, I only have one light fixture in my apartment with incandescent bulbs and I rarely use that light, and I have no trouble with the lighting.

I'm not normally the sensitive sort -- strobe lights and flashing video games don't bother me in the least

Besides being a photographer I am kind of sensitive to light, between the two it can get hard as when I'm out in the sun I almost always wear sunglasses. I can easily get eye aches without them. However I need to take them off when I shoot. And strobe lights can bother me.

Falcon

CFLs

[falconwolf]

I've never had a CFL burnout

They will do. My parents were early adopters (must be over 15 years since we had them)

I bought my first CFL 20 year ago, for US$20, and the first one I had burnout burnt out last year.

I remember the first ones cost about £10 and were massive, heavy things and they did flicker, and take five minutes to warm up.

Though as I say above the first one was expensive, it fit into the light fixture. I've never had a CFL flicker. Now, those first ones did take a minute or so to warm up, but not the ones I have now.

Falcon

Awesome. American Technology, lets build it....

[Jackie_Chan_Fan]

Overseas.

sigh.

This is why we lose folks...

If this technology becomes the new lightbulb standard... why dont WE, as in Americans, manufacture it for the world? It would create jobs, it would be in high demand, it would be good for our country...

I know its a silly idea.

Fluorescent lighting is just horrible.

[falconwolf]

I use 12 CFLs in 6 fixtures and I have no problem with them.

it's still expensive to get the good lights.

The latest CFLs I bought I got at Walmart for $3 something for a 2 pack.

LEDs aren't as bad, but they're quite bright and I personally cringe when people suggest that the alternatives to incandescent light bulbs are truly ready for prime time.

Now LEDs are expensive, and most are only good for spot lighting, only the really expensive ones are good for area lighting.

Falcon

CFLs

[falconwolf]

They're not full spectrum like sunlight

There are full spectrum CFLs, they cost more but are available.

-All of today's CFLs are NOT created equally.

This is definitely true. I recently read a report about CFLs, and almost all the bad ones were made in China.

Falcon

CFLs

[falconwolf]

if you've used CFL's on any scale, you'll certainly know that the quality/reliability of these products is miserable bordering on pathetic.

I have 12 CFLs in 6 light fixtures and don't have a problem with any of them.

I'm currently quite convinced that my switch to CFLs has cost more energy (and money) in terms of replacing failing bulbs than it has saved in electricity.

In about 20 years I've only had to replace 3 CFLs. Darn it, in earlier posts I said I only had to replace one but early this year I had to replace two more.

Falcon

Direct traffic to ad-heavy blog.

[falconwolf]

I RTFA, from Purdue U, and didn't see any ads, where are they?

Falcon

Safety of UV and HEV light

[Anonymous Coward]

White LED's emit considerable UV light and HEV (High Energy Visible) Light. As reported in http://health.usnews.com/articles/health/living-well-usn/2008/06/27/your-eyes-need-uv-protection-too.html , these radiations are harmful to your eyes. Those with macular degeneration should definitely keep away from harmful UV and HEV light.

Speed of light?

[Smivs]

This is old news. I submitted a piece about these on 15th May!
Here is a link to the article in question.

Efficency

[Anonymous Coward]

My only question about LED and the fluorescent lights that I cannot find anything on is a real cost/saving breakdown. We keep hearing about how much energy is being saved by us, but that does not mean that the technology should be considered green. If it costs us 30% more energy to make then and each one saves us 10% then that would be a net loss of energy of the light bulbs we have now. Also how much material is being used comparatively? Since business is involved and businesses typically do not have products that dont make them money you have to wonder if this new "Green" era is more about the all mighty dollar.

I already use them

[GottliebPins]

I have several recessed lights that were constantly burning out because of trapped heat, about one a week, and at $7 each the cost adds up quickly. I have since replaced them all with led lights. The led lights cost around $20 each. They don't get as hot and I haven't had to replace a bulb since I put them in 6 months ago. They pay for themselves.

Luddites

[Ullteppe]

What are all the luddites doing on a forum for geeks? Seriously, for any geek worth his/her salt, just replacing a vacuum-state technology with solid-state should be reason enough? :-)

Re:Luddites

[LeadSongDog]

Ok, I'll be the one to ask. How many geeks does it take to change a light bulb?

Re:Luddites

[Ullteppe]

11. 10 to argue which lighting technology is best, and one to change the bulb. Or did you have a different suggestion?

Anything modern = Luxury Goods

[KlaymenDK]

Compare this to the cost of a minor traffic accident where a tail light is cracked. No, you cannot replace the lens or any individual part, just the whole assembly. Instead of $100-$200 for an incandescent bulb assembly expect to pay $1500-$2000 for the LED tail light.

In modern cars, you cannot replace any individual part anyway. :( On my VW Golf, I recently had to spend DKK1700 to replace an entire headlight instead of only the front glass that was cracked (presumably DKK300, if it were to be had).

What about unning out of gallium??

[Anonymous Coward]

A few weeks ago there was an article posted about the world running out of gallium in about a decade. This is a critical part of even this silicon LED technology.

Re:[AC]Yea,

[everphilski]

Maybe some day the US will get the idea that you shouldn't put things containing mercury (and other things toxic to our planet) into household waste that will end up in landfills. Here in Europe we actually recycle (!) and CFL bulbs do not go into landfills, they are properly recycled so the mercury doesn't end up where it shouldn't be.

We do. Our recycling facilities take back CFL bulbs as do several commercial chains which sell the bulbs, most recently announced, the Home Depot. So it's just as easy as taking the burnt out bulb back when you go to purchase the new one.

That being said I don't know what all the fuss is about. Read the posts above - there are so many more meaningful sources of mercury that are "socially acceptable", yet we harp on CFL's. It's all posturing.

Cheap Abundant Light from LEDs

[Anonymous Coward]

I go to http://www.theledlight.com/ and order A-19 style bulbs. The A/C hardly ticks on anymore because the rooms are cooler, and I'm saving 20% on my monthly electric bill.

I like LED

[^_^x]

LED is my choice already. I have CCFL lights in my house, but they hum, give off harsh fluorescent light tinted with a yellowish hue to be less glaring and cold, and any outdoors in the fall/winter/spring just don't work because it's too cold. Since they come with power transformers that's a big waste of materials (why can't we just buy a quality converter base to plug them into?) and if you get a cheap one, the transformers can even overheat and catch fire - which I guess would be something to watch on LED "bulbs" too.

Really when I actually need light for a moment or two I've been using a 3-LED handcrank flashlight lately. For house lighting, I think LEDs are so small you could include a mixture of white, red, green, and blue then despite any gaps in the color spectrum, you could still tune the overall color to suit your preference. The biggest plus for me is that they are silent, as CCFL noise irritates me so much I just shut them off - but hey, I guess I'm saving power that way!

Very hot LED lights. Wasted energy?

[cciRRus]

The ones I've seen don't get hot, but then again they don't generate much light either.

I saw a couple of high output LED light setups and all came with a big heat sink. If I had remembered correctly, each LED is 1W and there were an array of 4x4 LEDs. When the lamp is in operation for some time, its heat sink gets really hot. You won't burn your hand instantly but you sure can't touch it for long.

Strange thing to me is that the amount of (wasted) heat energy is huge as compared to the amount of light emitted; yet these LEDs lamps are considered energy efficient.

Oh, there'll also be heat emitted by the power adapter as it converts AC from your wall socket to DC.

Re:Very hot LED lights. Wasted energy?

[drfireman]

Strange thing to me is that the amount of (wasted) heat energy is huge as compared to the amount of light emitted; yet these LEDs lamps are considered energy efficient.

"smellsofbikes" pointed out that incandescents radiate a lot of IR, so a lot of the wasted energy goes unnoticed. LEDs do waste a lot less energy, but a ridiculous proportion of the energy they waste is in the form of heat right at the socket. As I understand it now.

Yay this frees up Mercury!

[jameskojiro]

We can now use it in our flying mercury powered air cars that the ancient Indians once used before they blew themselves up when they dumbly decided to pick a nuclear war thousands of years ago with a slightly more advanced civilization.

Did someone mention CREE?

[yohnson]

CREE has already partnered up with a company to apply light fixtures for houses... This initiative to use LEDs for housing is not news. Now the question is does Purdue have a brighter light than CREE??? Converting cities is a growing news occurrence http://www.ledcity.org/

What do you mean in a couple of years?

[netruner]

I bought 3 this weekend at Wal-Mart - they were about $5 each, so it sounds like someone's on target. They have a somewhat blue cast to their light, they are dimmer than the bulbs they claim to replace, but they use a mere 1.5 watts.

The lack of brightness could also be explained by the fact that they're not really set up to give off omni directional light - all the LEDs are pointed in the same direction. This is great for can style lights, but not so much for other types.

I have to mention it again: 1.5 watts.

From algebra class...

[owndao]

Most of us picked up from our early math classes that higher order problems have *many* solutions. We seem to too often focus on "what would be the best" (as if this is a one solution problem) when what we should be asking is what things can out-preform a hot wire in a glass bulb in terms of efficiency (power in/optical power out), nasty side effects of life-cycle at producing light, and "other factors". That other factors part is probably going to change the selection of which technology is "best" quite often.

Our world offers many challenges other than first order linear. Don't forget those non-linear and probabilistic ones as well. As old-style resources run low and leave us to deal with their end-products I think that we are going to have to not limit ourselves in looking for solutions. Sorry for the mini-lecture. ;p

...but they'll suck in practice...

[roc97007]

I was looking forward to LED lights. I use compact fluorescents but don't like them for the mercury hazard and the slow turn-on time. Moreover, they don't save as much energy as you think, if used in situations where they're turned off and on frequently.

When they first came out, there was a positive advantage in longevity, (my first two CFLs -- purchased last century -- are still working) but "value engineering" since then has pretty much removed that advantage -- the CFLs I purchase now don't last much longer than regular light bulbs. And I have a sneaking suspicion that ten years from now we'll be looking back at disbelief at how we were increasing the mercury levels in our environment just to save a few kW-h.

LED light sources have a lot of technical advantages. They should use even less energy, don't have the mercury issue, and currently available LEDs last pretty much forever. So it could be a really good deal, right?

And yet... I harbor a secret fear that once LEDs become popular, in a couple of years, industry cost-cutting measures will remove all of these advantages.

Case in point -- have you noticed that stoplights are gradually being replaced with LED arrays? There was a big move in my town not long ago to replace all standard bulbs with LEDs, and quite frankly, they suck. Hard. Nowdays you can't find a stop light that doesn't have one-fourth to one-third of the LEDs completely out or randomly flashing.

Yeah, I know, it's a harsh environment and the city probably went to the lowest bidder, but there's a nagging part of me that whispers: as soon as LED light sources start to become popular, they'll start to suck, as they already do in traffic lights.

90% ???

[evilviper]

"You all know that incandescent bulbs are pretty inefficient, converting only 10% of electricity into light -- and 90% into heat.

Actually, I'd say they convert 100% of the electricity into heat (nominal)...

In fact LEDs and CFLs also convert 100% of the electricity into heat.

As do computers, TVs, electric cars, refrigerators, et al.