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Cree Introduces 200 Lumen/Watt Production Power LEDs
ndverdo writes "Cree just announced production power LEDs reaching 200 lumen/watt. Approximately doubling the previous peak LED light efficiency, the new LEDs will require less cooling. This should enable the MK-R series to finally provide direct no-hassle replacements to popular form-factors such as MR-16 spots and incandescent lighting in general. The LEDs are sampling and it is stated that 'production quantities are available with standard lead times.'"
Kudos.
The reduced cooling should help in lowering the costs of the LED versus the CFL and the reduced energy consumption will be a help as well.
A Shadeless room is a brighter room.
...seems to have the expert analysis. Some people are into flashlights so much and the LEDs that may be used in them, it's crazy what details they keep tabs on.
Post on the Cree MK-R LED at Candlepower Forums.
its pretty common, if not standard issue now to put a patch of phosphorous over a UV led to generate the final visible light in these high powered LED's. so its very similar to what you can expect out of a CFL (course these things measure in cm)
you do get advantages though, the starting UV is generated by a crystal and not an electric arch in a vacuum so its more "rich" and if its not half assed you dont get flicker
It won't be long before companies figure out how to get them to work. The Phillips L-Prize bulb uses the LED as a source of photons to excite a phosphorescent material. The actual light that the bulb emits comes from the outer surface of the bulb, so directionality of the LED is irrelevant, as long as they can excite enough of the phosphor.
Color *is* spectrum.
HTH.
--
BMO
jaffa cree!
I am sick and tired... of the government banning perfectly good items
Then consider yourself in luck! Because, y'know, TFA has nothing to do with anyone banning anything. Don't let me interrupt a good rant, though - Carry on, good sir, you rage against that machine!
Some of us would rather spend our money on more fun things than literally "keeping the lights on". Do whatever you want with your money.
How about letting people use the energy and resources they buy as they choose, instead of punishing them for it?
Obvious issues are quality of the light.
(Nothing of the following is about quality though:)
I have a very bright and 300+ lights christmas uhm.. "thread of lights" but I also use one of those older with small regular bulbs and those burn at a much much much yellower color so they look very miss-matching (the LED one is more "snow-white."
Also at the beginning the 3000k led spotlights I bought was rather disturbing because I wasn't very comfortable with the light color then but now I've got adjusted to it and don't think about it on day to day basis.
its pretty common, if not standard issue now to put a patch of phosphorous over a UV led to generate the final visible light in these high powered LED's. so its very similar to what you can expect out of a CFL (course these things measure in cm)
And we can of course trust that the manufacturing quality is 100% on these -- that the UV light isn't leaking out. There are health problems with certain wavelengths. However, I'm sure there's nothing to worry about...
#fuckbeta #iamslashdot #dicemustdie
For comparative purposes, an incandescent bulb puts out about 52 lumens per watt.
That's the theoretical maximum, that no bulb actually gets near. For example, a typical 60 watt bulb will give you 15 lumens per watt.
http://www.efi.org/factoids/lumens.html
When someone talks about "X Kelvin" as a colour temperature, they mean the spectrum emitted by a black-body at that temperature, which by definition is full-spectrum.
To a first approximation the sun emits radiation at 5800K.
A 90 second search revealed the following "A common choice is to choose units such that the maximum possible efficacy, 683 lm/W, corresponds to an efficiency of 100%"
http://en.wikipedia.org/wiki/Luminous_efficacy
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
If only! "An upper limit for incandescent lamp luminous efficacy (LER) is around 52 lumens per watt, the theoretical value emitted by tungsten at its melting point" (wikipedia). In fact a 40W tungsten bulb outputs 12.6 lumens/watt, up to 17.5 for a 100W bulb. Incandescent bulbs aren't even in the ballpark anymore.
As to whether some people assume all light is equal, I suppose some do. But others take it very seriously. It is not an overlooked issue.
They have to, since these things are typically ordered from overseas, with prohibitive return postage fees, and many times some manufacturer or vendor will try to become the cheapest by changing to LEDs of a crappy (i.e. fake) rather than Cree variety. When the item arrives, one usually has just a few days to ascertain whether it is genuine or if a refund needs to be requested from the payment service.
No, but outputting a mixture of just 4 pure wavelengths works well in initial studies.
Wikipedia has a list of luminous efficacies:
http://en.wikipedia.org/wiki/Luminous_efficacy
200 lm/W seems pretty good; the theoretical limit is around 300 lm/W for LEDs, and that's about 44% overall efficiency.
While it indeed is a commercial product, it's also a new industry milestone.
While I *do* love to hear stories like this, and I believe that LED lighting, in some form, is the future, it dissappoints me to see that so-called "white" LEDs still produce quite poor spectra. Check out the spectrum on page 4 of the datasheet given on the MK-R series page. Compare this to the sun's spectrum. Because these are phosphor-based LEDs, you get a relatively narrow blue-violet peak (the true colour of the LED), followed by a wider hump, peaking at about yellow (the broad emission spectrum of the phosphor coating, which is down-converting those blue photons). While this looks "pure white" when you look directly at the beam, it renders colours very poorly (i.e. the reflected light from objects looks the wrong colour). This is what causes LEDs and fluorescent lights to often make a room appear sickly and food look unappetizing. Ideally, we should strive for a light which closely emulates the sun's spectrum, but this is obviously challenging.
Fortunately, there are a few next-gen LED technologies on the horizon. Quantum dot-based LEDs seem promising. By making dots of a specific size, you can precisely tune the output wavelength of a QD LED. Presumably you can combine a whole bunch of QD LEDs, each tuned to a different wavelength, to approximate the sun's spectrum. Alternatively, certain types of organic LEDs offer the ability to tune the wavelength, and similarly, produce a composite device which has a more ideal spectrum.
Still, until these materialise, plain 'ol incandescents are the only cheap light sources which produce a nice, continuous blackbody spectrum. Sigh.
It's way, way, way more complex than this.
683lm/W is the maximum luminous efficacy for light, yes, but that's green light.
To reproduce in full the solar spectrum so that it is indistinguishable from white light requires you to produce a 'white' that produces light from about 400-700nm (UV to IR borders).
If you take into account flourescence and its effect on colour, perhaps 350nm is the top end.
This would take perhaps 180lm/W.
As you move from near-solar (or tungsten) identical bulbs to more limited 'whites' - you get about 250-400lm/W being the maximum.
This varies from pretty good white that you won't notice being different from actual white to something rather more limited, with just blue at 430nm or so, and greenish yellow at 560nm.
This will to a cursory glance look right, but will have truly wretched colour reproduction.
The basic problem is there is no consensus on how to price the destruction of non-renewable resources, nor generalized damage to the environment. I would not expect a tidy solution to that issue, ever.
I work with LED lighting every single day, and in one instance we had an issue where a soft dome got knocked off, the spectrum is actually so near blue it looks blue, its probably safer than a blacklight you used for your posters in college
The studies I've read that involve what you are referring to only applied to blue lights being on when a person is sleeping.
Just because you think white leds look white does not mean they don't have a nasty blue spike in their output spectrum. What you can't see can still hurt you.
this Cree MK-R isn't super suitable for torches
Certainly not suitable. It produces less heat than other LEDs, which are themselves not even suitable. For my torches i tend to stick to propane, MAPP, and acetylene.
And we can of course trust that the manufacturing quality is 100% on these -- that the UV light isn't leaking out. There are health problems with certain wavelengths. However, I'm sure there's nothing to worry about...
People are so delicate, it's a wonder the human race has survived this long. I hope you don't ever go outside during the day, sunlight is full of nasty UV wavelengths.
I don't care if it's 90,000 hectares. That lake was not my doing.
The NIH says you're wrong: http://www.ncbi.nlm.nih.gov/pubmed?term=fluorescent%20light
Care to provide any proof?
A year ago, I had no idea who "Cree" might be.
Then I bought one of these:
http://www.fenixlight.com/viewproduct.asp?id=151
It's the best pocket flashlight I have ever owned. Bright and useful on "low" power (32 Lumens) and very bright on high (105 Lumens). 500 minutes of light (over 8 hours) from a single AA cell on low, or 110 minutes on high. (I'm trusting the manufacturer's numbers here, but I can verify that it actually is bright and lasts a long time.) Anyway, that's a Cree LED, and it doesn't have the horrible bluish tint of older LEDs I have bought in the past.
More recently I bought an Ecosmart light bulb at Home Depot. "Ecosmart" is a Home Depot house brand, and uses Cree LED chips. For $10 I got a light bulb that claims to give equivalent light to a 40 Watt incandescent bulb, but seems brighter than that (I think because it's much more directional; it's in a downward-facing fixture so that's fine).
http://www.homedepot.com/h_d1/N-5yc1v/R-202188260/h_d2/ProductDisplay?catalogId=10053
And just two days ago I got a fixture that retrofits a 6" can fixture with an LED light. I bought one with the 2700K color temperature, because I like that better than the "colder" lights (bluer, which actually have higher color temperatures). I walked into the store planning to just buy a bulb for my can light fixture, and now I'm very glad I bought the whole Ecosmart fixture. I found an LED light geek web site, and the guy bought one of these just to do a teardown; he found 5 Cree LED chips inside it. Where I live, the power company is subsidizing these lights, so I only had to pay $20 for this light. This dissipates only 9.5 Watts, yet it's very bright. I love the design: it includes three spring fingers to hold it into place, but if you rotate it the fingers collapse and stop holding it. So two decades from now when the LED stops working, it will be easy to remove.
http://www.homedepot.com/h_d1/N-5yc1v/R-202240932/h_d2/ProductDisplay?catalogId=10053
So now I want to see Cree make some sort of flush-mount ceiling fixture. I have only found a few flush-mount LED fixtures, and they are all super expensive and I can't find the 2700 K color temperature. I did find one promising looking cheap fixture, but on eBay only and it's an import from China... I have no way to be sure of the quality, other than just buying one and trying it.
My current plans are just to install some fixtures that have air gaps for circulation, so I can use the Phillips LED bulbs (omnidirectional, not directional like the Ecosmart ones). I'm going to install one of these tomorrow and see how we like it. In case the URL doesn't work right, this is a "Project Source 2-Pack White Ceiling Flush Mount" from lowes.com.
http://www.lowes.com/pd_394606-43501-87822-01_0__?productId=3745415
Based on my experience with these lights, we are just on the cusp of these becoming mainstream and common. I've been buying these because they are subsidized, but electronics always gets cheaper over time, and within a couple of years or so LED lights should be cheap enough without subsidy that everyone starts buying them. (Even without the subsidy, they make sense long-term versus incandescent bulbs. If you have incandescent lights, consider LED rather than compact fluorescent.)
P.S. I haven't bought these, but I wish the office where I work would buy them. These are Cree replacement lights for standard fluorescent fixtures. Some companies are making LED lights that are the exact size of a T8 fluorescent bulb, with matching pins; for $60 or $80 or so each bulb, you can replace fluorescents (but you must rewire the fixture to bypass the ballas
lf(1): it's like ls(1) but sorts filenames by extension, tersely
That would be great if they lived on their own little planet. Not so much here, though, where I have to share it with them.
Considering that the entire surface of an incandescent, and most of the surface of a CFL, is the area where it dissipates heat, and that both incandescents and CFLs are ALREADY too hot to touch, it's a serious improvement.
It's basically not UV in white LEDs.
It's deep blue.
It is quite visible, and is the same colour as most normal blue LEDs.
To continue the comparision: The theoretical maximum you could get out of a light source is about 251 Lumen/Watt for a source of white light at 5800 K. So this new type of LED is near 80% efficiency.
When I started working with LEDs they just introduced the LM3909 oscillator - it allowed an LED (only red in those days) to blink for an entire year on a single D cell.
What keeps amazing me about LEDs is just how little energy they need to start lighting up. I'm not really into electronics anymore (was only tinkering with it since I was 11), but I recall that by using a FET for constant current meant you could be pretty flexible about the supply voltage (within limits, of course, the dissipation has to go somewhere), and by researching what it was (been a while) I came across other interesting ideas.
As a single, simple component, I find LEDs are about the most interesting ones to experiment with (and LDRs, and NTCs, and .. :) ). They are nice to introduce children to electronics because they instantly do something visible..
Insert
OK. Let me know when you want to install that heat pump, and I'll start bitching about the inefficiency of light bulbs. Until then, they are just as efficient as the electric furnace I can't afford to replace.
There aren't a whole lot of people in your situation where not only is it cold enough year round to need to use the heater, but you have one of the most costly heat sources available -- electric resistance heat.
If you have any top floor ceiling fixtures or wall sconces on outside walls, much of the heat is being conducted out of your house anyway so you're not getting 100% of the waste heat into your house so you could still save some money with more efficient lighting.
A heat pump system can save significant energy - you should talk to an HVAC dealer about systems, tax credits, and financing options, if you really are in a climate where you're using your heat year round, the energy savings could pay for the monthly finance charge and the system could pay for itself within 5 years.
On my bicycle I use a 30 or 40 year old chrome headlight made for use with a dynamo.
I replaced the 6v 2.4watt filament bulb in it with a high power white MES LED module designed to have 100 degree illumination. Powered by a single PP3 radio battery under the saddle, it produces a 15 foot cone of light on the road ahead of me lighting everything up to handlebar height (yes, I'm overvolting a 6v LED module but it doesnt seem to cause any problems, it still runs cool)
I have been a user for about 10 years. This ends Feb 2014. The site's been ruined. I'm off. Dice, FU
I've noticed a disturbing trend. Car manufacturers have been using the new lightning technologies to cram e.g. the headlights into ever smaller spaces. The resulting light beam still conforms to regulations, but because the peak intensity is much higher, those headlights are much more likely to dazzle oncoming traffic. The higher the light intensity of the lamp (lm/cm^2) the worse this will get.
When I was about 7 I was first introduced to electronics. I can still remember the anticipation of ripping into a Tandy (Radio Shack in the UK) mixed box of LEDs. So many bright colours and shapes.
Nowadays I buy them in bulk from China to refit my friends homes to save money. In certain cases such the the popular GU-10 50w downlighter bulbs, LEDs have been up to the job for quite some time if you ignore the high-power LED versions and buy units with 60 to 80 individual warm white LEDs. Been doing this for 2 years now and only seen a few failures, and all the recipients report lower fuel bills to an extent that paid for the bulbs in months. Failures are a fact of life with Chinese LEDs but if you make sure you buy 10% more than you need, you;re covered and the savings materialise as expected.
I have been a user for about 10 years. This ends Feb 2014. The site's been ruined. I'm off. Dice, FU
Not all white LEDs. Some have fairly broad spectrums.
There's a measure for that, though, and it's called CRI. A perfect CRI is defined as 100, and you'd think that incandescent would have a 100 CRI but it often doesn't. Great CRI is anything >=95 and halogens often achieves that, but general purpose incandescent lamps are usually less, sometimes horrifyingly less. LED is commonly worse than 95, but almost always better than CFL. For critical viewing LED isn't always the best choice unless it's made for the purpose, but that's true for any bulb. LED as a class looks better than FL and metal halide.
Here's a link to some LED bulbs with CRIs over 90: http://store.earthled.com/collections/high-cri-led-lighting-90-cri-led-lighting
If you want that looks good, LED is not problematic like CFL.
It takes 8 colour swatches and measures the rendering of those. It does not do a good job of looking at actual spectrum, and there are far more than 8 colours to worry about in the real world. Look at the spectrum of an LED vs CFL some day. The CFLs are very, very spikey with lots of holes, the LEDs are continuous with more gentle peaks.
We need a new system for measuring light quality, and indeed standards agencies are looking in to it.
LEDs of all types (lasers excluded) have no "spike". Typical half-power bandwidth is 20 nm. It's not smooth enough for color comparisons of paint or makeup, but it's nowhere near the monochromatic implied by "spike".
Since we're talking about cree lights check out their data sheets on their own LED lighting products. The graph on pg5 looks like a spike to me.
http://www.cree.com/~/media/Files/Cree/LED%20Components%20and%20Modules/XLamp/Data%20and%20Binning/XLamp7090XRE.pdf
There is virtually no selection of dimmable CFL, the few that exist are incredibly expensive
I think that's enough examples to show there are inexpensive dimmable CFL bulbs. However Walmart has more.
CFL sucks. We're better off with incandescent in the meantime.
I've used CFLs for more than 20 years and have not had a problem with them. That's not entirely true, I have had problems with them. In photography, photos on film show color casting with florescent bulbs, and with incandescent bulbs as well. The first CFL I bought I paid $20 for, and over the next 15 years it paid it's cost back in avoided cost. That is in energy not used and in not having to replace incandescent bulbs. I wonder if you enjoy wasting money.
Falcon
Should there be a Law?