LED Guru On InGaN-Based LEDs And The Future

Mayor Quimby writes: "EETimes reports that LED guru Shuji Nakamura predicts White LEDs to overtake the light bulb Mr. Nakamura is an amazing guy who is given substantial credit in the development of blue and white LEDs. Other articles about him can be found here and here. He "works from 7 a.m. to 7 p.m., 355 days a year, and says he has never taken a vacation." Also, check out this circuit board found in an LED flashlight that uses a single AA battery. It'll be nice when low cost knockoffs start flooding in from the Far East." I can vouch for the life of white-LED flashlights -- the ones I purchased more than a year ago from Holly Solar are still on their first sets of AA batteries. Not as bright as incandescents, but plenty for lighting up a tent or to keep from stumbling on a trail.

Comments

355?

[Fervent]

355 days a year

Back in MY day, we worked all 365 days of the year.

Re:355?

[Bios_Hakr]

Well, I work a 12-hour shift with 2 on and 2 off. So that is about 182 days a year. Out of that, I get a 30 day vacation. So I got 152 days. 5 days of sick leave gets me down to 147 days a year. I get a 2-hour lunch which kicks out another 12 days leaving 135 days a year. I usually show up late and leave early which kills about another 5 days. So that leaves about 130 days that I actually go to work. While I'm at work, I probable kill 30 days in the toilet reading a Neil Stephenson book, 30 talking about politics, 15 wondering what to do for lunch, 10 or so sleeping.

That leaves about 45 days a year of ACTUAL work. Oops, I forgot /.ing, make that about 5 days of work that I do.

Re:355?

[ChodeMonkey]

Lazy Slackers.

In MY day we worked 365 and 1/4 days a year and we liked it!

Re:355?

[spiro_killglance]

Luxury! In my day we used to work 10220 days a week, and when we got home each night, 4 years after breakfest, our dads kill us and jump up and down on our graves.

But you try telling the kids of today that and just won't believe you.

Traffic Lights

[doorbot.com]

Don't they already use banks of LEDs for the red traffic lights?

Re:Traffic Lights

[gnudutch]

Not in my town. However, all our school busses and some package carriers use LED-banks in place of tail lights. These banks fit the same form factor as the traditional round lens, so zero retrofit is needed. Sweet!

Re:Traffic Lights

[Stochi]

yes, and they also use them for green (and yellow possibly??). there is an intersection next to my apartment complex that has one of these newer light systems installed. they are BRIGHT (especially the green for some reason)! there is definately no mistaking what color the light is. it even hurts my eyes at night sometimes!

Re:Traffic Lights

[ewhac]

Yup, and 'round about these parts (San Francisco peninsula), they're starting to retrofit the green traffic lights as well, and man that shade of green is gorgeous to behold...

Schwab

Re:Traffic Lights

[fantomas]

Starting to change traffic lights over to LEDs in the UK as well, as far as I can tell. (A few round my area in London starting to appear for sure). Very bright.

Re:Traffic Lights

[Gordonjcp]

We have had these in Scotland for about 18 months now. Glasgow has quite a lot of them. One other advantage is that the housings are very strong compared to the existing glass lenses. Almost all the traffic lights near the football stadium at Ibrox are like this.

LEDs are the wave of the future

[Scrag]

Does this mean we will have *super* photon lights in the future?

If you combined this with a transmeta chip, the power savings would be enormous!! If one of those regenerative keyboards was thrown into the mix, these things would last forever.

my experience with LED Lights

[jonnythan]

LED lights certainly have their places. I own a Petzl Tikka headlamp that runs off three AAA batteries. I use this headlamp (along with a Princeton Tec Quest and a premier carbide lamp) for the caving i do here in the Northeast (specifically around the Albany NY area).

Anyway, the LED lamp uses three white LED's and doesn't put off anywhere near the light of the 2-AA princeton tec with a standard bulb. However, by way of comparison, it produces a more disperse light and it will last up to 150 hours on a single set of batteries, compared with 6-8 on the Princeton Tec.

The light is certainly whiter than most anything but maybe a xenon bulb (which uses tons of power). It has virtually no range, though. It lights up a nice hemisphere in front of me for a good 6 feet whereas the carbide and Princeton Tec can send a light several dozen.

I keep thinking that if they made a headlamp that had so many LED's in it that it sucked as much power as the standard bulb, it would be fucking bright indeed.....

Oh yeah, and the Tikka was almost $40 and the Quest was $15.

Re:my experience with LED Lights

[jonnythan]

This is the tikka.

And here is my Princeton Tec.

Yes, the Tikka is the 3 white LED lamp.

Re:my experience with LED Lights

[Primer 55]

Is any one making flashlights like that?

I've been carrying a Mag-Lite around in my backpack for years, and something that was smaller, weighed less and lasted longer would be awesome. If voltage is important, you could just use three smaller cells, but if it isn't, you could just run off one "D". The extra LED's might also come in handy, but I kind of wonder if that isn't more available, if at all, because of diminishing returns and/or the sticker shock it would cause?

Re:my experience with LED Lights

[reg]

This site has some interesting looking lights. Especially the 7 LED custom Petzl headlamp, which is unfortunately (1) expensive, and (2) out of stock.

I don't own any of their products, but was thinking of buying one of the various headlamps.

Regards
-Jeremy

Re:my experience with LED Lights

[jonnythan]

I'm not sure if diminishing returns would be a factor, but cost and size constraints certainly would. I've seen incandescent lamps that let you switch four AA's for a single D.

In any case, check out the link in the article..they make flashlights in the $20-$50 range it seems. I'm sure they're pretty decent, but LED flashlights are a different beast than incandescent. You don't get a spot of light surrounded by a really diffuse yellow the way you do out of a normal flashlight like a Mag. You kinda get all the light spread over a much wider range. The reflectors seem to do very little in focusing the light..I don't know why. As such, you don't get the same range out of them.

In any case, I personally don't like mag lites. Princeton Tec actually makes some wonderful incandescent flashlights that are small, powerful, and extraordinarily reliable (you can't imagine how hard caving is on gear like an extra small flashlight or bottle...you know those really hard Lexan Nalgene drinking bottles? I broke one a couple weeks ago..imagine doing that to your Mag...after you've had it submerged in water for a couple hours).

Er..anyway..I don't know if it works with incandescent flaslights, but using lithium AA or AAA batteries (energizer makes some) can easily more than double the expected life out of an LED lamp.

For a wider selection of LED flaslights check out http://www.karstsports.com/ledlights.html (yes, I like the store..sorry, I find it immensely useful and cheap with invariably good products). Enjoy.

Re:my experience with LED Lights

[Brian Kendig]

Check out Glow Bug, "http://www.glow-bug.com/". They stock all kinds of cool LED flashlights, the coolest being the Eternalight. I have that one, as well as their Photon (keychain) and NightStar (no batteries) flashlights. Very cool stuff.

Re:my experience with LED Lights

[Sedona Vortex]

Here is a link to some LED flashlights. http://www.glow-bug.com/main.html

Re:my experience with LED Lights

[HerringFlavoredFowl]

I've been using the White Light LED's caving for the last year. (and yes I mostly cave in Albany County).

My impressions on the White Light LED...
Very Energy Efficient
Very diffuse unfocused light source
Gives you awesome side vision
Don't go very far, because it is not a focused light source.
Great in the tight crawls of NY caves
Suck in large rooms, since they are so diffuse (WV Caves)
Suck when trying to look though semi cloudy water, Blue scatters better than RED turning water milky white. (Most NY Cave Passages)
Incredible battery life
Carbide is still the way to go...

When the white light LED's hit the market a few years back, I a grabbed the spectrum of one off of a Monochromator at work . The White LED's are a Blue Light LED with a Phosphor placed in front. Most of the Energy is emitted in the Blue (that's why the light looks so cold) and excites the Phosphor, which emits light in the other color ranges. I did notice from the trace that LED's have almost no RED component. Wish I had some of the trace data with me, I would post it. The Real trick for LED's is to push them farther and farther into the Deep Blue and UV, If you could get a device to emit at down around 253nm you could basically make a low voltage ballast free high efficiency light replacement that lasts 10,000 maybe 100,000 hours (1 to 11 years continuously on). Compact Low power UV light sources would be very nice, (though I question how long they would last working at 193nm and 157nm (the Photons have enough energy to start breaking atomic bonds in the substrate and window)).

TastesLikeHerringFlavoredChicken

Re:my experience with LED Lights

[fjordboy]

Ok...I really need to find some Carbide Lamps..My father wants one REALLY REALLY badly....does anyone know where I could purchase one? preferrrably a newer one? email me. fjordboy@iceball.net oh..and...leds are cool. (now this is an on topic post)

Re:my experience with LED Lights

[HerringFlavoredFowl]

I would say Bob & Bob's would be your best bet for a Carbide Lamp...
If not any of those caving events, MAR, NRO, OTR, Convention, TAG Fall Cave In, ect. (or any other cave related event that has the theme crawl till you bawl)

Bob & Bob (caving supplies)
PO Box 441
Lewisburg, WV 24901
800-262-2283 - Fax: 304-772-3076

And yes Bob & Bobs does sell white light LED's (so it is still on topic)

Re:my experience with LED Lights

[joekool]

http://photonlight.com
I carry around three of these in my pocket--blue, white, and red, and have for a few years now...these things are great...and a lot of these other places are getting the stuff from these guys, so buy from the source!

Thank LEDs for laptops!

[Anonymous Coward]

Did you ever realize there were no laptop computers before LEDs were invented? That's no coincidence. The little green-power-is-on incandescent light sucked too much power and made laptops a worthless concept. Thank LEDs for solving that bottleneck!

Re:Thank LEDs for laptops!

[BigBlockMopar]

And, of course, the big bank of neon lamps that would come on to indicate a low battery state.

Fortunately, small plasma discharge lamps like neon indicators are almost as efficient as LEDs.

<grin>

Let Light Loose

[Applied Alliteration]

Lovely LED's letting luscious luminence lift lonely lives. Light leaves love's lost luminairies lamenting, languishing, listlessly listening lest loveless labor limit life.

Lo! Love leverages light. Light limits love. Love learns light lessens lucidity. Loss lies lurking, luring lovers 'long looping lanes lacking love, leaving little. Less. Lust.


-Intense introspection
-Into interesting interpretations
-Involving intellectual indulgences

Re:Let Light Loose

[Mike Schiraldi]

Find friends. Fast.

Seek social surroundings.

--

spectrum on these?

[da5id]

Any one have any info about the range of light they put out?
Cuz I was thinking, no heat and low power, these would make good grow lamps . . .

Fire Jon Katz. Hire Neal Stephenson. (make this your sig too)

Re:spectrum on these?

[Maurice]

Check out the online LED museum
here

Re:spectrum on these?

[HerringFlavoredFowl]

Actually you want Green LED's that matches up with the absorption line of Chlorophyll. Mind you they are expensive and you might be better off with normal plant fluorescent lamps, they have about the same efficiency. But the Chorophyll line is the only line you really need to provide to a plant.

TastesLikeHerringFlavoredChicken

Re:spectrum on these?

[fl1t]

ummmm.. if plants absorbed green wavelengths, they wouldn't be green, right?

Re:spectrum on these?

[kol-chaim]

I don't know what you've been smoking, but green is precisely the color you don't need. Red is probably the color you're looking for, but the reality is that plants not only absorb in various spectra, but the required range can vary somewhat between species. Did you know that not all chlorophyll is created equal?

There are photochromatic analyses that have been performed on chlorophyll absorption (and there is more than one type, found in various ratios in plant materials), but even that data doesn't entirely match up with experimental results.

What I want to see is someone producing LED clusters which target specific frequencies needed by plants, without wasting energy on the unused light spectra. And even then I'll want to see solid experimental data backing up its effectiveness.

Stimulated emissions (as in flourescent) might be the only way to adequately spread the incredibly narrow frequency of LEDs into a broader, more useful spectrum.

Re:spectrum on these?

[Admiral Burrito]

What I want to see is someone producing LED clusters which target specific frequencies needed by plants, without wasting energy on the unused light spectra. And even then I'll want to see solid experimental data backing up its effectiveness.

Am I crazy, or does that have implications for long-term space flight?

Re:spectrum on these?

[James Ray Kenney]

Ultraviolet is already available.
Check out the new Ultraviolet photonlight and the LED musieum.

Re:spectrum on these?

[BigBlockMopar]

Any one have any info about the range of light they put out? Cuz I was thinking, no heat and low power, these would make good grow lamps

I think most (ahem!) herbs grow best under a greenish to bluish glow light. You should be able to find that out for sure in any good book on amateur hydroponics... Grow lamps, for example, always seem to be a more blue-green glow than an ordinary fluorescent tube. And incandescents don't seem to do much at all.

If that's the case then, don't bother with an array of white LEDs. They're incredibly expensive. Instead, go for an array of blue (still expensive) or green (common) LEDs.

Hi-intensity green LEDs are fairly available, just quickly checking the back cover of my Digi-Key catalog, you can buy Panasonic green clear LEDs in T-1 3/4 packages for $199.70 per thousand pieces. At 20mcd @ 565nm @ 30mA @ Vf=4, they might grow plants pretty well, if you have enough of them. (There are far more intense and efficient green LEDs out there, I just flipped over a catalog.)

There are also 1500 mcd blue LEDs available from the same source (www.digikey.com). On my older Canadian edition of their catalog, the 1500 mcd blue LEDs put out at 470nm, If=20mA, Vf=3.5V. Panasonic part # LNG992CFBW, if you wanna check out the datasheets on their website. A thousand of them will cost you over three grand.

It would, for sure, be an interesting project. Remember to budget for a large DC power supply to run these, as well as homebrew PC board to wire all these, because you're sure as hell not going to do it by hand.

All about LEDs

[Peter Lake]

LED museum

No Need for "Brighter" Buttons

[Puck The Trickster]

Does this mean they can finally make calculators brighter? Also go white & blue instead of that oh so putrid green and off green? Sorry, but when I think of "waves of the future", I don't think LED. When I think of the future, I think nano-tech, space stuff, and the like. Besides, how many advances in the world of LED displays can really be made? "Well, we can do diffrent colors now." "Well, we can...um...make it blink, and stuff." You know, somethign just popped in my head. Are Laptop displays LED? Oops.

Re:No Need for "Brighter" Buttons

[chemguru]

Calculators use LCDs (liquid crystal displays)... not LEDs. Same with laptop displays.

Re:No Need for "Brighter" Buttons

[gnudutch]

Actually LED screens would be pretty sweet, if they could build them pixel-sized. They're bright, don't require crazy voltage like back-lights do, refresh super fast, black blacks and white whites....

Not only traffic lights...

[chemguru]

Along with traffic lights, why not normal street lights? Perhaps an array of about 10-20 white LEDs could produce the same amount of lums as a standard Mercury Vapor lamp with much less energy required.

household lighting

[Barbarian]

I was thinking of how household lighting might be implemented with white LED's---

I guess you'd need a lot more LED's (or banks of them) then bulbs. Since LED's are also DC beasts, you'd need to convert to DC with a rectifier circuit from the standard 110 VAC. I guess this would be best done once (instead of having a rectifier at each lighting location), and seperate 5 V (or 12 V or whatever) circuits for lighting only done throughout a house. This would be best applied to new houses only. Having a seperate rectifier at each light location (i.e. to replace traditional bulbs) would probably be wasteful and expensive.

Re:household lighting

[Jeff DeMaagd]

No, not really. Practically everything ELSE in your house does AC->DC conversion. It can be done with between 70-90% efficiency. LEDs are just that much more efficient and they don't give off that much heat per unit of light power/

An L.E.D. does not have a filament to "heat-up" and thus there is not lost energy, making L.E.D.s approximately 3-5 times more efficient than incandescent bulbs.

I wonder how it compares with flourescent power wise.

Is it wasteful & expensive to have all that circuitry? If LEDs really do get 100,000 hours of duty use, that's 100-200 TIMES the claimed life of incandescent, so for every LED unit you toss in the trash, that compares to maybe 150 glass bulbs in the trash. Flourescents are claimed to get maybe 10,000 hours.

Re:household lighting

[Jeff DeMaagd]

LED diodes are not power diodes, for one thing they often can't handle 5V in reverse or forward current mode. Power diodes can take a significant beating because they aren't designed in a delicate manner to give off light. I would want protection circuitry in there, as well as the fact I'd just want straight DC fed to it just so that the duty cycle per LED isn't on/off/on/off, that way fewer LEDs are needed to produce a given amount of light, and the circuitry can be packed behind the lights somewhere.

Still, even with conversion circuitry, that's pretty cool. Many don't like the slow startup times and colors of flourescents, many are used to the "warm" color of incandescents to use in the home.

Re:household lighting

[1010011010]

I actually can't stand the flicker of flourescents as much as I disklike the spectra they produce. I use incandescents for this reason. A workable LED light source for the house would be great. Especially if the house were wired for 12v DC -- I could then have house-wide battery backup.

________________________________________

Re:household lighting

[GypC]

But flourescents have that insufferable strobe effect and lack the pure white color of the led. I don't think you could embed flourescents in epoxy to make them impact-resistant.

"Free your mind and your ass will follow"

Re:household lighting

[FrankDrebin]

Here's an idea - just put a few dozen LEDs in series in one direction across the AC line to match the forward-bias voltage of a hunder-some-odd volts. Do it twice, in parallel, with the second string connected the other way to it lights on the other half of the AC cycle. Do this all on one chip (a few dozen LEDs on one chip, like millions of transistors in a CPU). Now you have a direct light bulb replacement. No fancy power supplies, extra electronics, or extra cost.

All royalties gladly accepted.

Re:household lighting

[Detritus]

You can get rid of the strobe effect by using a high frequency ballast. Unfortunately, many buildings still use the old ballasts and those horrible cool white bulbs.

Re:household lighting

[Ronin441]

you'd need to convert to DC with a rectifier circuit

What you talkin' 'bout, Willis?

LED's are, after all, diodes. If you feed one an AC voltage, all that happens is that it turns on whenever the voltage is high enough. That means it's off for a touch over 50% of it's duty cycle. But you don't actually need to do any rectification; the LED effectively does it itself.

5 V (or 12 V or whatever) circuits

Just string together more LEDs in series until you've got enough to take the voltage. Simplifying just a little, if your LEDs have a breakover of 2.2V, and you're working from 110V power, just string 50 of the wee beasties together. (I suspect that this is what is sone in LED traffic lights.)

The real reason that LEDs aren't used for lighting much yet is capital cost: particularly for high brightness, an LED array is way more expensive than an incandescent or fluorescent light.

Re:household lighting

[Jeff DeMaagd]

I agree, I would be willing to try LEDs, although you can get color correct flourescents (very close to 6500K, an official standard for neutral white color in movies and TV). Others say that you can get rid of the flicker by using high frequency LEDs.

Re:household lighting

[Jeff DeMaagd]

I should have said high frequency ballasts (for flourescent bubls only).

Re:household lighting

[dillon_rinker]

The funny thing is, you've got a patentable idea...and I could probably patent it.

Re:household lighting

[BigBlockMopar]

Do this all on one chip (a few dozen LEDs on one chip, like millions of transistors in a CPU). Now you have a direct light bulb replacement. No fancy power supplies, extra electronics, or extra cost.

Nope.

While you're right about the LEDs in series - especially since the diodes would then protect themselves from being reverse-biased beyond their PIV ratings, this isn't practical.

The problem is that LEDs are still less efficient than a comparable semiconductor junction. While it's easy to build a rectifier diode or other power semiconductor that will stay cool in a small package, an LED is a special case because it has such a high voltage drop. Most of that energy does leave as light, but some as heat.

Getting heat away from a power semiconductor's silicon die can be tough enough, without the added problem of diffusing light away from the junction in such a way as to be practical as well. It's just not going to happen.

Re:household lighting

[BigBlockMopar]

you'd need to convert to DC with a rectifier circuit What you talkin' 'bout, Willis?

Actually, you do want to be careful that your diode string has a peak reverse voltage rating greater than the AC to which you're going to connect it.

For this reason, it's prudent to include a 1N4004 or better in series with your string. As with any diodes, when LEDs are reverse-biased and you exceed their breakdown voltage, the current quickly runs away and the diode fries. The maximum allowable reverse current of LEDs is generally much lower than most other kinds of diodes.

Why LED lights might not take over

[Kiwi]

Tungsten lights are inefficient beasts. They have been obsolete for many years because of folresent lamps.

So why haven't floresent light taken over?

The light from floresent lamps is, emotionally speaking, "cold" and "unpleasant". I have an Inova light (a cheap clone of the photon light), and the light from it by itself is cold and harsh compared to tungsten lights.

- Sam

Re:Why LED lights might not take over

[toybuilder]

modern fluorescents [...] perhaps they aren't sold in the energy-guzzling US though?

Nah. We use 500W halogen torchiere lamps sold just about everywhere (hardware store, thrift shops, heck even the green grocers). $15-$20 each.

This is really for those hard to reach places

[Thalia]

The real place for the white, or colored LEDs is in locations where replacing the light is a pain in the *ss. Think about it. If you need to replace a traffic light, you need to turn off the light, put a cop there, and drag out the truck and the guys to replace the bulb. Instead of incandescent, by using LEDs you can have replacements every 5+ years (because you'll have 40+ LED's and a few burned out ones won't be a problem). This makes perfect sense, and makes the added cost of the LEDs an excellent investment. (trust me, traffic cops on overtime make way more for the hour plus it takes to replace a bulb than the cost of 50 green LEDs.) This is why in the Bay Area, almost all red lights are already LEDs, and more and more yellows and greens are being changed.

Similarly, think about lights in places where they are difficult to replace. Embedded lights in offices come to mind. Anywhere were work has to stop to replace a light, it makes sense to pay $30 for a bulb. In the home, on the other hand, the cost of replacement is negligible. So, LEDs probably won't take over until they are almost as cheap as standard bulbs. On the other hand, I'd love to replace the pool lights with LEDs, because I have to lower the water level, which is a complete pain, to replace those lights.

Thalia

Re:This is really for those hard to reach places

[michaelmalak]

Just a nit: the "green" light in a traffic signal would actually need white (or possibly green LEDs plus blue LEDs), not green LEDs alone, since green and red LEDs are indistinguishable to many color-blind people. In standard traffic signals, the green light has a lot of blue in it, so that it appears white or whitish to red/green color-blind people.

Re:This is really for those hard to reach places

[abischof]

Can't they tell just from the position? That is, top = stop, bottom = go?

Alex Bischoff

Alex Bischoff
---

Re:This is really for those hard to reach places

[I.AM.BLORT]

yes I can, but try that in texas, where they have turned many traffic signals on their sides. really throws me for a loop when I am driving from the east coast to the west coast of the US.

Re:This is really for those hard to reach places

[maggard]

Er - couple of facts:

• Incandescent traffic lights get changed out ~every 5 years.
• LED traffic lights last ~15 years.
• LED traffic lights initially cost more but generally pay back in power-savings in 3-5 years.
• LED traffic light manufacturers are corrently operating at capacity to supply the increasing demand for their product.
• Incandescent & LED traffic lights are built to put out about the same amount of light although the LED ones appear brighter. This has to do with the numerous bright-points of a LED-lights vs. the single uniformly bright surface of an incandescent.
• Studies have shown that having folks rely on light-positions is unsafe. It requires too much cognition while the training of ColorA=Stop/ColorB=Go is easy & effective for human brains.
• Traffic signals aren't uniformly laid out in North America. While many are vertically arranged horizontal is popular too. Of the horizontal ones many use red lights on both ends.
• Masking incandescent or shaping LED lights is also becoming popular. I can't recall the shapes but the some lights now use them to indicate the colors (I live a few blocks from a city that does this.)

On a related topic:

• Color-blindness is much more common in men then women.
• It is also much more common in European-stock folks then non-European
• It's most common in Americans of Irish descent although there isn't a correpsonding percentage of color-blind folks in Ireland. It is theorized that perhaps color-blind folks were greater affected during the Potato Famine (unable to distinguish bad potatos) and so selectively left Ireland in greater numbers then interbred in the US.
• Green LED lights use about the same percentage of blue as incandescent green lights.

Re:This is really for those hard to reach places

[Apotsy]

Traffic signals aren't uniformly laid out in North America. While many are vertically arranged horizontal is popular too. Of the horizontal ones many use red lights on both ends.

Say what?! I've never seen a traffic light that didn't follow the top/left rule. If it's vertical, red is at the top. If it's horizontal, red is on the left. I'd imagine exceptions are rare indeed. What cities/towns have traffic lights that don't follow that rule?

Re:This is really for those hard to reach places

[maggard]

Many places in Quebec use red-lights on both ends of a horizontal array. The city of Laval is an example.

See, you learned the world is bigger then you thought today.

Re:This is really for those hard to reach places

[michaelmalak]

Can't they tell just from the position? That is, top = stop, bottom = go? Not at night from a distance. In fact, yellow and red traffic signals cannot be distinguished at night from a distance by some red/green colorblind people, but this is not as big an issue as distinguishing green from red traffic signals.

Re:This is really for those hard to reach places

[theancient1]

Montreal also has the horizontal ones. In some parts of New Brunswick, they use horizontal ones for pedestrian crosswalks and vertical ones for intersections. The horizontal traffic lights tend to be the ones that use different shapes -- square for stop, circle for green, yellow diamonds.

Re:This is really for those hard to reach places

[Apotsy]

See, you learned the world is bigger then you thought today.

You know, since you said "North America" in your original post, I thought about putting something in my reply about how top/left is the convention, unless "those dirty Canucks do it differently". However, I decided to be nice and leave it out.

Now I wish I'd left it in..:-P

Re:This is really for those hard to reach places

[maggard]

by Apotsy on Sunday December 17, @03:49PM EST

You know, since you said "North America" in your original post, I thought about putting something in my reply about how top/left is the convention, unless "those dirty Canucks do it differently". However, I decided to be nice and leave it out.

Now I wish I'd left it in..:-P

Muchos gracias. Pity you weren't aware Mexico is also part of North America.

Not only is the world bigger then you thought, you also turned out to know less about it then is generally expected.

:-P

Re:This is really for those hard to reach places

[gle]

You see only one light at night, so you can't tell which one is on if you can't see the color.
I've always thought the lights should have different shapes: Why not have a red square, yellow triangle and green disc? It would be so much user friendly to the color-blind.

____________________

Next hurdle - omni-directional LED lighting

[Sodakar]

If you don't have a LED light, go get one - it's compact, durable, extremely bright, and battery life is awesome. Quite enjoyable! I personally love the Photon II, but be sure to read Brock's LED Flashlight Page first, before buying a dud like the NightHawk, which is not bright at all.

Now that I'm done with links - I'll say this - while LED lights are great for directional lighting, they are not good at all for omni-directional lighting. This is because the reflector is housed inside the LED itself, and the light will always be facing the direction of the LED plate.

Now... I wonder how difficult it would be to get that LED plate inside the plastic/resin housing into a shape of a cylinder, and install it in place of a standard tungsten filament? If that is possible, then the LED light will truly be able to replace all lightbulbs... Not just the directional ones.

Hmm, I guess I don't have much to say other than the good links up top, and my hope for tomorrow's LED, household lightbulb. If you experts have something to say about the possibility of the cylindrical LED plate, I'm all ears. I surely don't know if it's possible or not.

Re:Next hurdle - omni-directional LED lighting

[Jeff DeMaagd]

I think plastic lenses might solve your conundrum to an extent. Also changing the design of the plastic case it's packaged in can help nicely too.

White LEDs are nothing new ...

[mheller6]

Take a look at: http://www.iaf.fhg.de/mf/Nitrides/LUCOLED/LUCOLEDs .htm

CREE and Nakamura

[ereuter]

http://biz.yahoo.com/mf/001013/news02_001013.html

"Hunter announced Cree had landed the services of Shuji Nakamura, who has attained legendary status in the optoelectronics field."

I read this article a couple months ago and I haven't heard anything about it since. None of the articles given in the story mention anything but his professor job. Is Nakamura working for CREE or not?

Re:CREE and Nakamura

[jchawk]

From what I have gathered from www.silconinvestor.com; he is working on a contracted basis.

very true

[rebelcool]

this is the same reason 1000W halogens are used in stage and screen, while it does take an enormous amount of power (and you wouldnt believe the heat generated by a tiny 1000W bulb thats about the size of one of those large outdoor xmas bulbs), it makes a very natural warm light.

Re:very true

[NevDull]

Ah, but with the ability to make red, green, blue, yellow, and white LEDs, couldn't the combined light produced be tuned to emulate natural light?

-Nev

Re:very true

[Maurice]

No, because the spectrum of sunlight is continuous, so you would need an infinite number of LED's at wavelengths between 400 and 700 nm.

Re:very true

[Dahan]

LEDs aren't monochromatic. They emit a continuous spectrum too, just not across the entire visible range.

A strange idea from timothy

[Bilestoad]

"It'll be nice when low cost knockoffs start flooding in from the Far East."

Why? Because the product you end up with will be flimsy? Because you'll have to return the first three before finding one that works? Because the company that developed this product will stop receiving any return on their R&D? Because your Uncle is some slave-labor king in Malaysia? You sure won't be "vouching for the life" of any low-cost knockoff.

If you think about the success of the MAG light, you will realize that low-cost knockoffs probably wouldn't even be attractive to most people.

The Infinity task light linked to is a good little light. If I could only have one LED light it would be the Photon Micro Light, but the Infinity is still a good option if you don't want to use button cells. It could benefit from some reflective material around the LED perhaps, as the light output is much less than the Photon. Maybe I'll polish the metal around the LED... hmmm.

Re:A strange idea from timothy

[BigBlockMopar]

If you think about the success of the MAG light, you will realize that low-cost knockoffs probably wouldn't even be attractive to most people.

Thank you.

Just when I was starting to despair over the fact that some people think Wal-Mart is a perfectly reasonable place to buy a VCR and flimsy disposeable cars like Hondas and Toyotas choke the roads around me, it's nice to see someone else who still respects that "100% plastic-free" school of product design.

I keep a MAG light in my glove box. It comes in handy when I need to use my 24-year-old pickup truck to jump-start my boss's Integra, which won't start when it gets below 10F outside.

I go out of my way to buy the real thing, not the crappy made-in-Taiwan knockoffs.

Is this really a white LED?

[diphead]

>> "Nakamura said he placed a novel phosphor
>> over his blue chip to get a white light."

Is this really a white "LED"? Sounds like a blue
led activating phosphorous to me, which hardly
seems would be the holy grail.

Don't get me wrong, it's great about Nakamura
developing the blue led, I just don't think we
should call this a white "LED".

Re:Is this really a white LED?

[eclectro]

Agreed. When LEDs were first invented they were encased in differing colored expoxy housings (with very limited success) so there could be "violet" leds. This technology should be given a different name - maybe "solid state activated phospher." Better yet - maybe there should be naming contest.

Save the "white light emitting diode" for a P-N junction that emits white light.

LEDs on Late Night Radio

[Alien54]

I first heard of these a couple years ago on late night radio. Typically you could get them from places like the C. Crane company.

Of course, these were very popular among certain folks who were stocking up for the Y2K crisis last year. (Everyone who remembers the end of Western Civilization, raise your hands).

Actually not a bad technology, but a little pricey if you do not have a real need for it.

C. Crane company has some cool things, although they are more oriented towards the radio geeks

real-world uses of LEDs for lighting

[gkanai]

a friend of mine works at a top notch NYC lighting design firm. When I sent him the EE Times article, he replied: "LED can be electronically dimmed and when in an array for red, blue and green LEDs, you can simulate full spectrum color mixing. The low-tech way to do a seamlessly color changing lightbox, for example, would be to use dimmable fluorescent with color sleeves or three colors of neon." "If you find yourself at the Shoreham Hotel Bar, or Stueben Glass Showroom, you will see some of our work. The only problem with LED is that is prohibitively expensive. There were only a handful of quality LED suppliers 2 years ago. I'm glad it's catching on though, hopefully prices will go down." "Neon is $30/ linear foot installed in NYC. Raw LED strips can cost a minimum of $150/ft. sans necessary programming and playback devices." "Colorcorp and Color Kinetics are doing some interesting display lighting with LED."

40 Hours My Arse

[SubtleNuance]

I think the proponents of LED lighting linked above may have streached a little when they state:

A standard incandescent bulb will typically burn out in less than 40 hours.

That sees a little bit low to me... unless you mean 'standard' being the homemade lightbulb created with a vacuum pump and a piece of yarn.

Re:40 Hours My Arse

[dmaxwell]

Incandescent bulbs are not inherently short lived. They have been known to last for years burning continually. Cycling is what kills bulbs. Think about it. A cold bulb has very little resistance and there is a tremendous amount of inrush current when initially powered up. This current heats the filament and the heating increases resistance thus limiting the current to reasonable levels. During the switchover from cold/low resistance to hot/high resistance, the filament expands and fairly large amount of material is sputtered from it. The same thing happens in reverse when the bulb is switched off. (This property also means that a small incandescent bulb can be an excellent power regulation component.) The filament contracts and SOME of the tungsten vapor is redeposited back on the filament. Most of the tungsten vapor condenses back on the walls of the bulb. Turning a bulb on and off is just like flexing a piece of solid core wire back and forth....a piece of wire that gets thinner each time you flex it. You may have noticed that your porch and garage lights often last for years. Even a 100 watt interior bulb can last through several months of regular cycling.

This reminds me of another factor for incandescent longevity: power. A 40 watt bulb doesn't get as hot and will last far longer than that 100 watt bulb.

I once read about a 40 watt bulb at a firestation that burned continously for 16 years! Does anyone remember a primary source of info for this? It may have been one of those yellow sodium jobbers which are possibly the longest lived incandescents of all. When using low power and continous duty cycles, incandescents can last a long time indeed.
Come to think of it, 40 hours was the amount of time the first practical incandescents lasted. This was over a hundred years ago and I do believe they have perfected them somewhat since then!

Of course, none of this addresses being dropped and moved about. Even a 40W bulb is a power pig compared to an LED unit that may be far brighter and efficient using less power.

not really

[ArchieBunker]

A few more cents for a 1N4007 rectifier diode and possibly a resistor.

Aircraft Landing Lights

[trolebus]

I was talking to one of my friends and he showed me this LED he bought from Rat Shack. It was about 1 inch in diameter and an inch tall. (Brute force I know) Anyways we put it on a table and off of 5v we saw the red dot on the celing with the lights on. Apparently about 20 of these LEDs are put in a case with a lens and used for some aircraft landing lights.

No way

[HEbGb]

The white LED's are not anywhere close to 1% of the output of a HPS or mercury vapor bulb. And I see no evidence or data that the LED's have any substantial increase in efficiency over the mercury vapor lamps for similar light output.

Workaholic

[Ektanoor]

From 7 am to 7 pm, 355 days a year and no vacation? What's so big on this. Does this makes his LEDs better? I know LOTS of people, in well known "lazy" Russia working 12-16 hours a day. From 10 am to 11 pm, 1pm to 4am, 7pm to 7am. Or like "dusk to dawn" (HEY we are not vampires! It's just no one BOTHERS you). And many work one, two, three years without vacations, on holidays and Sundays. On the screen I am seeing the reflection of one guy with 6 years work in a row (oh daaaaamn! Yeap, need vacation!..)

Yeah fellow Japanese and Chinese are traditional workaholists. But frankly I believe that our fellow americans and europeans have also such epidemy catching their lifes... At least some friends say things like "sorry I'm in the 14th hour, going to sleep". So I don't think that workaholism will made his LEDs shine brighter...

LED + Mirror projectors will kill the CRT(finally)

[Hieronymous Coward]

The big problem with LCD and mirror-chip projectors is excessive heat. With white LEDs, this won't be a problem. The pixel-definition device (chip or LCD) can be kept small and cheap, while the display (reflective board) can be big and cheap. Finally we'll have cheap, high definition screens. They'll be light and thin, too.

LED's inhibit aircrash post-mortems

[toybuilder]

LED's are terrific. Increased reliability, higher efficiency, lower power consumption, higher peak output, and better heat dissipation.

BUT, one 'negative' side effect of greater LED usage is the NTSB will have less forensic evidence after aircrashes (at least with smaller private planes without a flight data recorder)...

At moment-of-impact, the filament from a lit bulb breaks apart differently from an already-burned out bulb or from an operable-but-not-lit bulb.

Here's an article that describes filament analysis. And two reports, one where LED's prevent filament analysis (search for "filament analysis") and another where analysis showed the status of indicators (search for "filament stretching")

Slightly off-topic, but interesting, I think.

Re:LED's inhibit aircrash post-mortems

[Ares]

Although there's nothing that says the FAA (in the US) can't mandate the use of incandescent bulbs on aircraft

Re:If anyone remembers...

[Gordonjcp]

I think you may be right. But the sequels, particularly the 4th one, were utter crap.
They were mostly written by Arthur C. Clarke's co-writer.

Re:A strange idea from timothy. (Nope, and Yup.)

[timothy]

Dear Bilestoad:

a) that's not my idea, it's Mayor Quimby's. All I did was post his story.

b) But I would like to see cheap knockoffs in the hopes that several years down the line the overall quality and variety of LED devices available would be greater.

Just like all the Japanese companies which currently are renowned for high-quality products (Nikon, Honda, Seiko) were correctly considered imitators for a long time, but aren't now. They made (cameras / cars / watches) of acceptable quality cheap, and quickly ramped the quality up. Hondas today are high-quality, low-maintenance, reasonable price -- a net customer benefit. (I say that as a Ford owner with what is basically a Mazda engine.)

So. Wasn't a strange idea from timothy, but now it is.

timothy

Our eyes are have only three color sensors

[dara]

An infinite number of LED's at wavelengths between 400 and 700 nm is not required to emulate sunlight for humans. How do you think TV, film, and printing work? Humans have only 3 separate color sensors and therefore the earlier poster is correct, a sunlight color could be achieved with 3 LED's. However, this is not how most white LED's work anyway (read the recent Technology Review article for explanations), and the white LED's I've seen have more blue content than sunlight. For flashlight applications, I've found this to be acceptable and perhaps even preferable.

LED's are not going to do well in home lighting for quite some time if ever. Fluorescent lighting is more efficient, reasonably color balanced, and much much cheaper per lumen output.

Re:Our eyes are have only three color sensors

[Maurice]

Not quite. If you have seen the CIE chromaticity diagram, you will know why. It looks sort of like a half ellipse. When you pick three primary colors, these form a triangle on the CIE chromaticity diagram, and all colors that are inside the triangles can be generated as linear combinations of those primaries. All colors outside, cannot be represented, even though they are visible and distinguishable by human eyes. Theoretically you would need an infinite number of monochromatic primaries, all lying on the edge of the cromaticity curve in order to represent all visible colors. Also, human eyes do have only three types of color sensitive receptors, but these have continuous response over a range of wavelengths (the response curve looks like a Gaussian). TV, film and printing work by playing a variety of tricks on the human eye and their quality cannot be compared to the quality with which we see the real world.

(Insane_work_ethic == BAD)

[-=[ SYRiNX ]=-]

He "works from 7 a.m. to 7 p.m., 355 days a year, and says he has never taken a vacation."

And this is supposed to be a good thing? Obsessing about anything to the verge of lunacy, and sacrificing all the other things that really make life worth living, is hardly a healthy way to live. The quality of life on this planet is only going to get worse as long as people keep praising this kind of unreasonable work ethic.

I can't wait for LED Christmas Lights...

[MioceneMan]

LED Christmas lights would be perfect. I put up lots of Christmas lights, and every year my kids egg me on to put up more. Every year I curse the broken strings. Reliable LED Christmas lights would save me a lot of time, and probably lower my electric bill.

No patents for you Big Guys, it was posted here on Slashdot first...

Re:I can't wait for LED Christmas Lights...

[apayne]

I built a set last weekend... with currently available LED's. An entire string of 100 takes
only 4.3 watts (as compared with the small incandecent sets that take 210watts/100).

The voltages at which a standard LED operates
would allow for 70 lights/segment (as compared
with 50 incandecent bulbs/segment).

--
Downsides include:
The cost. LED's can cost anywhere from $.12 to
$.30/each for high brightness ones (in quantities
of 1000).

As LED's are solid state devices - all the LED's
need to be oriented with the same polarity for
the string to function at all.
--

I built a string of 100 using a dead incandecent string (containing two segments of 50 bulbs each)
using red,green and yellow LED's, (2) 2000ohm resistors, and (4) 1n4007 diodes as a bridge rectifier. It requires only 36mA for the entire
string.

They're DIODES - let them rectify

[vik]

It's not a big deal. All you need is a centre-tapped transformer if you want to get quick & dirty. Let one half of your LEDs light up on the positive half of the phase, the other half on the negative. Use of capacitors to double light output is left as an exercise to the diligent student.

I tend to use amber high-brightness (6.5 candela) LEDs because they'll run off 2xAAA with no electronics other than a weedy resistor. Inserted into one of those glasses-like head lights instead of bulbs, I can run them for months on the batteries that won't work in my pager.

Vik :v)

Reflectors

[stinkydog]

What these led lights are missing is efficient lense / reflector systems. Given the small 'filament' area (the elusive point source of light) of the LED emitters it should be reasonably simple to construct a parabolic or elipsoidal reflector. Once the gee-wiz factor is used up and people actually start desiging fixtures to use these lamps, watch out. By ganging LEDs together (already done) and focusing the light some really cool stuff is possible. Stinkydog

Re:Reflectors

[kobotronic]

Actually, some LED assemblies for diffuse types are sold with tiny reflectors, fitted as a chrome collar around the base of the LED casing. I don't think it's used much these days, since modern high efficiency and high brightness LEDs are typically encased in what looks like clear acrylic, and the lens formed in the top of the LED, are reasonably efficient for most purposes. It usually depends on the shape of the die inside, and they're different from manufacturer to manufacturer, and depending on what chemicals are used to produce which wavelength. The Nichia blue and white LEDs are the best and brightest around, and their built in lenses are focused enough for practical flashlight purposes.

What, not use 90% of the energy to make heat?

[tulare]

But my french fries will get cold! (Just kidding)
Actually, I was very recently involved in a project using this technology (which I believe used Nichia's instruments). The idea was to use an array of white LEDs bounced off a secondary reflector which could be repositioned for focusing a la Maglite. We did run into a number of difficulties in reflector design, but I believe this technology is certain to take off. A funny point to Shuji Nakamura's statement that:

The resultant white LED can lead to a flashlight that shines for 35 hours, up from the present six-hour limitation for an incandescent flashlight bulb...

In testing an initial mockup, we managed to make six LEDs run off a pair of D-cell batteries for over two weeks without a loss in performance! Might be time to sell off that stock in Duracell...

led and mags

[ananke]

well, i love LED's, but honestly, have you ever tried to defend yourself with a mag-lite and a led-based flashlight? :)

sorry, but when it comes down to ass-whoopin', mag does an amazing job, i guess that's why even cops are using them. i've never clubbed anybody over the head with same efficiency as i did with mag-lite.

heck, yes, i'd love to have an LED flashlight with the magnitude and ass-whoop-power of a 4-double-d mag-lite :)

I dont think so, Tim.

[geoffeg]

From the fourth link:
2. LONG LIFE: The light emitting portion of an L.E.D. has a 100,000 hour life span. A standard incandescent bulb will typically burn out in less than 40 hours.

Really? I can't think of any light bulb I've ever had that lasted less than a few weeks (and yes, I realize that means hours of on-time). Someone is buying really bad light bulbs!

Geoff

Put video cameras in the cockpit instead.

[kobotronic]

Yeah, that is too bad that they couldn't tell which of the cockpit annunciators were illuminated at time of impact.

But really, NTSB / FAA would look silly for mandating or even proposing the continued use of ancient filament bulb technology in instrument illumination when LEDs are better, brighter, cooler, less ambiguous, more power efficient and more reliable. With LEDs you're less likely to have a 'bulb' burn out and give you a dangerous wrong readout, and typically a LED annunciator will outlast by ages the device or dashboard assembly it was part of. It seems to me that it is more important that the guys driving the things can see what they are doing, than the NTSB being able at postmortem to determine the state of things from little quaint glowing bits of filament.

There's also glass cockpits in many modern jet airliners, with relatively few free standing annunciators at all, most of the readouts appearing superimposed on the smart displays. You can't use a filament analysis on those either.

I agree that there is a need for cockpit data in crash analysis to help future accident prevention, but I'm disappointed that they don't opt for better and more reliable data gathering methods.

The 'black boxes' recovered at crash sites seem to always have really cruddy and ambiguous sound signals requiring very subjective interpretation, and only a dozen or so flight control readouts with little more than the flight path and state of the control surfaces recorded. It seems that the amount of data gathered by those antique recorders don't exceed more than a few kilobits of data per second, and with the capacity to only record for an hour or so before the tape loops and erases the old signal (providing the magnetic erase head even works.)

If FAA mandated it, modern digital technology could monitor much more data, and log all the flight controls and all the display readouts by use of inexpensive cockpit video cameras and video recorders pointed at the consoles, where forensic analysis could easily identify with an accurate timeline the status of illuminated annunciators, whether LED or filament bulbs.

Crash and fire proof solid state memory devices with no moving parts are all very much possible to manufacture, and presumably on cost comparable or below those of the mechanical contraptions that constitute the black (orange) boxes today.

There is a concern about intrusion of privacy on behalf of the pilots with the prospect of having a video record of cabin events, and I can understand that, but at the same time they are driving plane full of people, it's a big responsibility and it's important that when things go wrong that we can understand how and why. For instance, we couldn't tell for sure what happened to that EgyptAir liner, since no video record could tell investigators exactly what the crew were doing and for what reasons. The controversial audio record was ambiguous at best.

The video tapes of such a proposed monitoring system would only be used by NTSB after a crash anyway, and the proposed configuration in the designs I've seen would be aimed to only have the consoles and flight yokes in view, so off duty officers with their hands off the wheel would be free to goof off unseen by forensic investigators.

I modified my power boat

[Lumpy]

This past fall I replaced ALL my navigation lamps and instrumentation lamps with the super brightness led's that are out. The white LED's in my anchor light ar 3 times brighter than any commercial anchor light plus I am easily identified by friends by the whiter light. Oh, and I can leave all lighting on for 8 hours without a measurable drain on the boat's battery's while before the LED conversion I had to start the engine every 2 hours to keep the battery from going dead during late night fishing or loitering in the lakes.

LED lighting.... why do we still screw with incandesant lamps?

Note quite

[GSearle]

Our eyes do have three color sensors, and these are designed to respond to a broad spectrum to cover all wavelengths in-between these colors. Consider a pure yellow wavelength. Both red and green sensors in our eyes respond to this light, giving us the impression of yellow.

The problem with R,G,B light sources arises with reflective materials, which don't reflect just R,G,B light. A material that reflects a yellow wavelength of light will look bright yellow under a continuous-spectrum light source, such as an incandescent light, but will appear a dark, muddy color under even the brightest R,G,B light source.

This is why artists and other professionals will only use incandescent light sources in their work. Flourescent and plasma sources have an irregular spectrum to them, and cause weird color distortions in the subjects being illuminated. When an efficient light source comes out that has a smooth spectrum, they might reconsider. Incandescent lights have a nice spectrum, but they are hot!

LED market forces

[la1n]

Lots of great discussion, but as an avid LED fan, I noticed some info was missing.

(1)Of course LEDs will not replace incandescent lamps where "aesthetic/artistic" spectrum is an issue. Market forces must center on businesses replacing their half century old mercury vapor florescent lamps. Count the number of 40 watt tubes at work. Factor in mercury disposal costs along with energy costs.

(2)LEDS don't really burn out like mercury tubes or incandescent filaments. It's more like a half life for brightness. Barring electrical surges, LEDs last forever, but eventually get too dim to be useful.

(3)I noticed that buses use LED lamps for marker lights, turn signals and brake signals. So, LEDs are already replacing incadescent indicator lamps.

Why LEDs?

[cr0sh]

Hey, I love LEDs as much as the next geek, and I believe they could take over regular lighting (for a long time I wondered why they were only used on the third brake light, and nowhere else, then the turn signal and brake lights for commercial vehicles came on the market, and now one of the Cadillacs have them - should trickle down to regular vehicles soon). Still, I think there is another option not too many people know about:

Tesla bulbs.

These bulbs work in a similar fashion as a flourescent bulb. Essentially, the bulb looks like a normal bulb, but with a wire running up the middle in a glass tube, tipped with a small metal sphere. The inside of the bulb is "coated" with a material that flouresces in the presense of intense radio waves. When Tesla was experimenting with them, simply holding one in the presence of a Tesla coil was enough to get them to light, but they were really meant to be "directly" connected to the Tesla coil output.

IIRC, Tesla's original bulbs weren't very bright, but they showed the concept well. Later inventors have experimented with the system, and built bulbs in which the Tesla coil formed part of the "filament", with some of the electronics in the base of the bulb - meant to be screwed into an ordinary socket and run off of normal houshold current. These bulbs were much brighter, and supposedly last for over 50 years of continuous operation.

I don't know if they were ever manufactured on a large scale. They were VERY expensive, supposedly costing over $30 each, but given their longevity over ordinary bulbs, this wasn't a real issue. They were meant for commercial installations, where changing a bulb was difficult or dangerous.

Does anyone know more about these bulbs, and whether they still exist (I tend to wonder if the new compact flourecents have taken over)?

Worldcom - Generation Duh!

LED Automotive and Traffic Lights

[BigBlockMopar]

Don't they already use banks of LEDs for the red traffic lights?

And lots of buses and trucks are starting to use them for signal and brake lights. New Mercedes S-series are including them, as are the new Cadillac DeVilles.

And, if you're in the Toronto area, you can take a drive through the corner of Eglinton East and Sloan. That's a block west of Victoria Park Avenue. The traffic lights there have LEDs.

HP's Agilent Technologies advertises the benefits of LEDs, besides the obvious energy efficiency and reliability increases.

The best part is that it takes a few milliseconds for the tungten filaments in conventional bulbs to light up when electricity is applied. With a GE 1156 or 1157 (depending on whether or not your car has combined brake and parking lights, either one of these is the defacto standard on about 95% of the cars on North American roads), if you're travelling 75MPH, you will travel about 15 feet in the time it takes for those filaments to light up.

And that means that if some jackass with an SUV and a cellphone planted to the side of his head is tailgating you, he will see the lights as you slow down, possibly giving you and him an extra 15 feet or so. This can make the difference between a small bent-bumper accident and no accident at all.

After some jackass hit me in May - two months after I picked up my beautiful old 1976 Dodge Ram, I took matters into my own hands. My bumper is trashed, but he bought me a new one, which I haven't put on yet. The old bumper is bent, but still strong. Stronger yet since I welded steel angle iron behind it, and then cross-gusseted the rear of the frame. The bumper is now fortified steel attached through soft brass shear pins to the truck's now-reinforced frame.

The plan?

Well, the last jackass who hit me mashed his radiator against his intake manifold. And my Class-4 trailer hitch, which is welded to my frame, didn't have a ball on it, so as my bumper bent, the hitch was rammed through the side of his cylinder block. I could see his connecting rods. Silly little Honda go bye-bye. All because the idiot had to "feed" his Tamagochi. I'd love to sue the government of my province for entrusting anyone who is stupid enough to buy a Tamagochi with the priveledge of operating a motor vehicle.

The next time someone hits me, I expect my bumper not to bend, but to simply fold up or down as the sheer pins snap. This will mean that the impact force of the next silly little tinfoil Japanese unibody car that hits me will be dissipated entirely on the ends of my gussetted Detroit plate steel frame rails. The rear 8 feet of my frame are criss-crossed with steel stock welded in at 2 foot intervals. Sure, I'll have to pick up my bumper and toss it in the back of the truck, but a moment's inattention from the schlep following me will result in catastrophic damage to his vehicle.

When I get around to putting on the new bumper, I'm also going to swap LED brake lights into the truck. I've already planned out most of the voltage regulator that they're going to need, but until I know for sure how many MCDs of light are really necessary for brake lights, I can't choose a diode and therefore can't choose a voltage drop which would allow me to finish the regulator design.

Anyone know of any good automotive-brightness red T-1 3/4 LEDs?

Japanese white light?

[BigBlockMopar]

This won't be the first time that the Japenese help the White LED (the third letter stands for death). I seem to remember a little incident called World War II.

I think the Japanese got to see more than enough white light during WWII. Maybe that served as the inspiration for the white LED?

Around here, most Jews seem to drive German cars; most Chinese people seem to be driving Japanese cars.

Personally, while I wouldn't touch a Japanese car with a ten meter cattleprod, but speaking as a former tech at a TV station, no one has ever made a better TV set than Sony. As long as the Japanese allow North American manufacturers to sell their products there, I have no problem with the Japanese selling their products here. Competition and innovation are mutually beneficial.

Forgiveness is an interesting thing. And a good thing.

LED Lighting in Space - a prediction.

[BigBlockMopar]

Am I crazy, or does that have implications for long-term space flight?

You're probably crazy, but yes, it does.

Fluorescent lights are not as efficient as LEDs, though they're still more practical for the moment. And they're bulky, the ballasts are heavy, and they're fragile. The LED will first see general lighting use in space, but I don't think it's ready for that yet.

And yes, it's another one of those evolutionary improvements that will improve the technology of space travel. I'm still holding out for the revolutionary ones, like superluminal travel and gravity manipulation.

White LED Notebook Backlights are here now

[BigBlockMopar]

Actually LED screens would be pretty sweet, if they could build them pixel-sized. They're bright, don't require crazy voltage like back-lights do, refresh super fast, black blacks and white whites....

White LEDs are already being adopted as replacements for the fluorescent tubes or electroluminescent sheets being used as notebook backlights. You can now get large (notebook display sized) sheets of frosted white plastic with white LED junctions embedded for use as backlighting in new notebooks. It will basically work like an electroluminescent backlight but without the inefficient and failure-prone inverter. I saw them advertised in an electronics engineering trade magazine that I get.

Re:Light Emitting EPROMs

[BigBlockMopar]

I have always preferred Light Emitting EPROMs, though they're a lot more expensive and don't last as long. (plug one into your breadboard backwards)

Or try programming it on the wrong voltage. (Ooops.)

Re:A strange idea from timothy. (Nope, and Yup.)

[BigBlockMopar]

Hondas today are high-quality, low-maintenance, reasonable price -- a net customer benefit.

Sure. Disposable and expendable, like their owners.

Uhh... Unfair comparison.

[BigBlockMopar]

So that's my car. It's messy right now, need to clean it and would if it weren't raining here. It's not flashy, but the tape deck works and I have a nubby cover on the steering wheel

Listen, I'm not a Saab fan, and I'm not an Escort fan. Neither is a car that I like.

But to compare the reliability of a 14 year old turbocharged luxury car against a 5 year old econobox is patently unfair.

Because of its age, it's probable that the Saab had more miles on it. It's also probable that the Saab, being a turbocharged alleged sports car was also driven harder. It's a luxury car, too - more complicated, with more things to break or wear out.

And, it's definite that because the car was nine years older than the Escort, there was a lot of decay to little things that nickel-and-dime you to death unless you know how to fix them yourself. Insulation on wire decays. Rubber breaks down. Gaskets dry up. Contacts get corroded. Keep your Escort around another 9 years and you'll learn all about that.

I drive a 24-year-old Dodge Ram pickup truck. The other day, the connector to my voltage regulator failed. It was corroded. The regulator didn't have a reference for the voltage on the battery, so it assumed the battery voltage was zero, and therefore pegged the charging current. +50A charge on my gauge - I pulled over as soon as I could, because my battery was boiling and my electrical system was running at 22 volts. (Only blew a headlight, though.) I pulled out my multimeter, checked a few connections against the service manual (kept stashed under the seat), found the bad connection, cleaned it with a pencil eraser, and the problem was fixed.

This is the sort of thing that will happen with *any* older vehicle. Period. There's no escaping it. If you like older vehicles and choose to drive them, you have to know what to do and be prepared to do it.

It's nice, though. Driving older vehicles has taught me to be resourceful, a skill useful everywhere. And I can diagnose a problem quickly, and have a lot of practice in assessing the severity of a situation.

The truck is insured for liability only, and pickup trucks are cheap to insure. $34/mo gets me $1,000,000 coverage in a city almost as big as Chicago. Besides that, I'm not paying out monthly car payments, so that money can instead go to fund other things - like a 401(k).

And besides, I just like the thing.

With a good tune-up, my truck is also the only vehicle I know that doesn't need to be plugged in to a block heater on a cold winter's night - it'll still start, first shot, on the coldest morning of the year. I frequently have to jump-start my boss's 2-year-old Integra. Why? Because, while my truck may be crude, it was built to last, and I take good care of it. The Acura was built to perform flawlessly for the first 100,000 miles and then be scrapped.

My truck gets an oil change - cheapest 10W30 oil and filter I can find - every month (3,000 miles). Every month, I also pop off all the wheels, check the brake linings, lubricate the parking brake cable with silicone grease, check the wheel bearings and balljoints looking especially for looseness or torn dust boots, and grease all the suspension. Takes about 2 hours every month. New air filter if it's visibly dirty or every three months, whichever comes first. I clean and regap the spark plugs every three months, checking the compression, timing and vacuum advance at the same time. (I'm impressed with the Bosch Platinum plugs I put in early this summer!) And while I've got the motor warmed up and I'm in my coveralls, I pop a vacuum gauge on the old Carter BBD carburetor and balance the metering rods, and re-set the idle.

Every fall, I spray another coat of paint on the underside of the body to prevent the floor and frame from rusting in the salty wet snow. Every week when there's snow on the ground, the whole underside gets washed off with hot water at a car wash. And every summer, I set aside at least one project that I'd like to do, usually because I enjoy them. Last year, I gave my truck the gift of air conditioning. This year, I'm going to repair some old rust damage on the truck, replace the windshield (there's a small chip in it), tap a couple of small dents out of the body and then treat Methusulah to another coat of Chrysler Forest Green Metallic paint.

Re:Uhh... Unfair comparison. (still offtopic ;) )

[timothy]

BigBlockMopar wrote: "Listen, I'm not a Saab fan, and I'm not an Escort fan. Neither is a car that I like.

But to compare the reliability of a 14 year old turbocharged luxury car against a 5 year old econobox is patently unfair.

Because of its age, it's probable that the Saab had more miles on it. It's also probable that the Saab, being a turbocharged alleged sports car was also driven harder. It's a luxury car, too - more complicated, with more things to break or wear out."

True on all counts, and I don't fault your taste -- I don't like most other people's cars, and frankly am surprised that I like the S900 *or* the escort (though in different ways).

The comparison *is* unfair, but not completely; the Saab was driven by the proverbial little old lady, and was approximately the same mileage at purchase that the escort was.

I must admit to lacking your car-sense (very worthwhile, my admiration for yours), though I'd like to develop more. Still, I do go in for routine maintenance, make sure that oil and filters are up to par, inspect tire pressure ... not much, but from what I've seen more than most people do!

Given slightly different circs, I might go in for a pickup with a garage to play with it in, too -- right now, no room. Ah well!

timothy