# Cree 231 lumens per watt !



## videoman (May 9, 2011)

Perhaps not yet in production, but that is amazing for the bar to be raised by that increment.
http://technews.tmcnet.com/news/2011/05/09/5496319.htm


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## LEDAdd1ct (May 9, 2011)

Just to be clear, is the article stating:

-it is a single die?
-it is around 4500K?
-its forward voltage is about 2.86?
-it is being powered at only 350mA?

2.86 volts * .350mA = 1.001 watts

Holy cow!

That's nuts!

When can I buy the warm white and high CRI version? :twothumbs


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## jtr1962 (May 9, 2011)

Amazing, and honestly not a whole lot of room for improvement at this point ( at least for standard blue plus phosphor LEDs ). I never thought we would reach this level by 2011. I had figured by 2015, or more realistically 2020, you might finally hit close to 250 lm/W in the lab.


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## Harold_B (May 9, 2011)

I would certainly like to find more detail. Like how are they getting the increase? Better out-coupling with the phosphor layer or have they developed their own high RI encapsulant or is it the die itself? Does "standard room tempurature testing" imply 25C instead of the 85C being adopted by most producers? If they can translate those gains into product in the near future then that would be incredible! I would like to see a 6500 K four die myself.


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## Thujone (May 9, 2011)

This seems very promising, 350ma at room temp. The future looks bright.


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## jtr1962 (May 9, 2011)

Harold_B said:


> Does "standard room tempurature testing" imply 25C instead of the 85C being adopted by most producers? If they can translate those gains into product in the near future then that would be incredible! I would like to see a 6500 K four die myself.


I believe by standard room temperature testing they might be running the LED on a large enough heat sink so the base plate is more or less at room temperature. Obviously the die will be somewhat warmer. I also think as LEDs become more efficient the 85°C being adopted by some producers will be less and less relevant. An LED only heats up because it's less than 100% efficient. At 231 lumens per watt, I'd estimate you're getting at least two-thirds light and only one-third heat. A 100-watt replacement using such an LED would only use about about 7.5 watts (plus ballast losses which might be another 10%), and produce around 2.5 watts heat. Difficult to imagine any part of the lamp, even the LED die itself, reaching 85°C even in a totally-enclosed fixture.


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## IMSabbel (May 9, 2011)

I hope they write a paper about this like last year.

The blue base diode needs to have at least 85% wall-plug efficiency for something like that. Incredible. 

This also changes the cooling paradigma: More heat is generated due to stokes losses in the phosphor compared to the the die itself... with obviously worse thermal pathways.


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## Harold_B (May 9, 2011)

The need to test at 85C is always relevant (in my opinion) since there are a lot of areas in the world where ambient is greater than 25C. I'm thinking about applications like street lights in arid locations not just a replacement light bulb.


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## jtr1962 (May 10, 2011)

IMSabbel said:


> I hope they write a paper about this like last year.
> 
> The blue base diode needs to have at least 85% wall-plug efficiency for something like that. Incredible.
> 
> This also changes the cooling paradigma: More heat is generated due to stokes losses in the phosphor compared to the the die itself... with obviously worse thermal pathways.


That actually makes a good case for remote phosphor which spreads the heat over a relatively large surface area. This makes cooling the die almost trivial. If we use my earlier hypothetical 100 watt replacement for an example, you have ~1.4 watts Stokes losses (dissipated easily over the globe by using remote phosphor), and a mere ~1.1 watts at the LED die. Even with a small heat sink, the die will practically be at ambient ( at most 10°C above).


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## Lynx_Arc (May 10, 2011)

LEDAdd1ct said:


> Just to be clear, is the article stating:
> 
> -it is a single die?
> -it is around 4500K?
> ...


 
what is even more nuts is with these they could make direct drive 2AA alkaline battery lights that put out over 231 lumens that would stomp current 2AA boosted lights in stores. The days of the 2D cheap plastic flashlights could be back again (with LEDs in them instead of incan bulbs). Essentially when these efficient emitters become mainstream the days of cheap incan flashlights could be numbered.


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## HarryN (May 10, 2011)

There of course remains the minor challenge of surface brightness. General lighting applications are not very sensitive to this, but flashlights certainly are. At low current densities, surface brightness is going to be low regardless of the technology.


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## CKOD (May 10, 2011)

HarryN said:


> There of course remains the minor challenge of surface brightness. General lighting applications are not very sensitive to this, but flashlights certainly are. At low current densities, surface brightness is going to be low regardless of the technology.



Lumens per mm^2 is lumens per mm^2 regardless of the current density. If they did this on a 1mm^2 die, then the surface brightness of this at 350mA would be similar to an XR-E at 1A, regardless of current density. 

That being said, bring on the highly efficient dies in good themal packaging so we can drive the **** out of them.


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## HooNz (May 10, 2011)

I was poking around on a circuit board today , using a D11 as it was a bit dark in there and i noticed for the first time actually , that when i was looking at the bands to read the values of resistors (old style) those colours did not show up right and had to swap to a incan .

Just a thought on these Leds and colour rendition?

Paul


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## Norm (May 10, 2011)

HooNz said:


> Just a thought on these Leds and colour rendition?
> Paul


 Google high CRI Paul.
Norm


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## CKOD (May 10, 2011)

HooNz said:


> I was poking around on a circuit board today , using a D11 as it was a bit dark in there and i noticed for the first time actually , that when i was looking at the bands to read the values of resistors (old style) those colours did not show up right and had to swap to a incan .
> 
> *Just a thought on these Leds and colour rendition?*
> 
> Paul


 
Dont be so picky and expect a lab experiment to have a 105 CRI, 2700k CCT, with the die at 100C? :nana:

On a serious note though, Its all a just progress. They release an LED (like the XM-L since that just came out) but only cool white is available, they come up with a happy phosphor receipe for neutral and warm whites, (like where we are with the XM-Ls now) and then eventually high CRI whites. 

But XP-Gs with high CRIs are available, but manufacturers dont put those in flashlights, or neutral or warm LEDs since that doesnt sell like CREE R5 OVER9000LUMENS. But as you noted, CRI is definitely vital in a lot of applications.


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## jtr1962 (May 10, 2011)

HooNz said:


> I was poking around on a circuit board today , using a D11 as it was a bit dark in there and i noticed for the first time actually , that when i was looking at the bands to read the values of resistors (old style) those colours did not show up right and had to swap to a incan .
> 
> Just a thought on these Leds and colour rendition?
> 
> Paul


Honestly, I find cool white LEDs make it MUCH easier to read the white lettering on black background present on most integrated circuits. As for resistors, incans might offer superior ability to distinguish between red and orange bands (and sometimes they pick colors which are really close), but it comes at the expense of being able to distinguish violet and blue from each other, or even both from black. For resistors then I think something like a 4000-5000K high-CRI LED might be ideal. Nowadays though I mostly use surface mount resistors which have the value numerically marked on them. Much easier than the color band system.


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## shao.fu.tzer (May 10, 2011)

I want these LEDs... now... Then I'm going to make bulbs for the entire house and save a fortune on my lighting bill!!!
WOW... 231 Lumens per watt... I'm salivating over here... XM-Ls are going to be obsolete soon! Unless these new LEDs
are like 60mm in diameter... There's not a lot of data there... Just some Cree representative that COULD be talking out
his arse.

Shao


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## jellydonut (May 10, 2011)

4500K?!

That's basically daylight color. Provided of course they are an even white and not rose, purple, or green. 

This is a fantastic achivement by Cree, and of course, not unexpected. LEDs seem to follow Moore's Law as well as their transistor-based silicon cousins. I am surprised, though, that this was achieved using a 4500K LED rather than a less useful, less pleasing 6000K LED.


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## LEDAdd1ct (May 10, 2011)

jellydonut said:


> I am surprised, though, that this was achieved using a 4500K LED rather than a less useful, less pleasing 6000K LED.


 
I had the same exact thought!


If we assumed for the sake of play that Cree used the same letter/number efficiency scheme they use now, like R2, R3, R4, R5, S2, etc., where would 231 lumen per watt LEDs sit?


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## Yoda4561 (May 10, 2011)

If we use the XR-e or XP-G binning at 350mA, it would be a U2 bin.
edit: This differs from the XM-L bins because those are done at 700mA, this is a ~7 bin or so jump from the current production items, so if we jump that far in the XML range it would be the equivalent of a V3 bin.


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## LEDAdd1ct (May 10, 2011)

Thanks, Yoda.


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## HumanLumen (May 10, 2011)

Just when everybody is happy, I chime in! I'm slightly dissapointed as I was looking forward to the 200lm/watt devices that they had last year and the 176lm/watt they had the year before that. Effectively, we will probably have to wait at least 2 years before we see any real increase in surface brightness/mm2 as they are still experimenting. It's a bonza acheivment make no mistake, but I was hoping to see somthing soon as all we have had in the last 3 and a bit years are effectivly repackaging of devices with a little surface brightness inprovement.

Sorry for being a right miserable so-and-so

HL


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## BigRiz (May 10, 2011)

To put things into perspective, I did this quick chart of record R&D efficacies as announced by CREE in the last few years


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## Lynx_Arc (May 10, 2011)

BigRiz said:


> To put things into perspective, I did this quick chart of record R&D efficacies as announced by CREE in the last few years


 
would be nice to see an overlay of LEDs at those efficiencies available at those ratings at those dates in time.


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## BigRiz (May 10, 2011)

Lynx_Arc said:


> would be nice to see an overlay of LEDs at those efficiencies available at those ratings at those dates in time.


 
I will try to gather that data if I have time


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## Lynx_Arc (May 10, 2011)

BigRiz said:


> I will try to gather that data if I have time


 
thanks :thumbsup:


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## jtr1962 (May 10, 2011)

Lynx_Arc said:


> would be nice to see an overlay of LEDs at those efficiencies available at those ratings at those dates in time.


Just going by my admittedly faulty memory, it seems like production lags lab results by about 2 years. My best guess is 3rd quarter 2013 for these to make it into production.

Now with blue emitters not far off 90% efficiency, I think there's going to be more focus on the phosphor end. Either that, or improving the efficiencies of red and green to match blue. We can in theory approach 400 lm/W with decent CRI. We just can't do it with blue plus phosphor LEDs.


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## flashflood (May 10, 2011)

Yoda4561 said:


> If we use the XR-e or XP-G binning at 350mA, it would be a U2 bin.
> edit: This differs from the XM-L bins because those are done at 700mA, this is a ~7 bin or so jump from the current production items, so if we jump that far in the XML range it would be the equivalent of a V3 bin.


 
if continue this pace they do, run out of letters they will!


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## monkeyboy (May 10, 2011)

Well at least this is something to look forward to in life.

Sadly, I'm not being sarcastic.


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## HooNz (May 11, 2011)

Thanks Norm , Will do , and thanks to the others also .


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## Calina (May 11, 2011)

Is this a photo of the elusive Cree laboratory animal ? 
http://www.led-professional.com/tec...new-efficacy-record-in-lab-231-lumen-per-watt

It sure doesn't look like a single die.


Nah ! :duh2:


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## AnAppleSnail (May 11, 2011)

Calina said:


> Is this a photo of the elusive Cree laboratory animal ?
> http://www.led-professional.com/tec...new-efficacy-record-in-lab-231-lumen-per-watt
> 
> It sure doesn't look like a single die.
> ...


 
Caption: " The innovations from the lab are the basis of the advancement in the XLamp product range, like the XLamp MT-G"

I'm thinking that they grabbed a cool-looking stock photo of Cree critters.


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## Calina (May 11, 2011)

I'm thinking that you are right.


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## flashflood (May 11, 2011)

Calina said:


> I'm thinking that you are right.


 
Yeah, if this is in the lab, it's not likely to be pretty yet.

Remember what the first transistor looked like -- you won't be putting a billion of these in a square inch:

http://gallery.vibada.com/d/106-1/first+transistor.gif


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## monkeyboy (May 11, 2011)

In terms of efficiency per mm^2 die area, there hasn't really been any significant improvement in production LEDs since the cree XR-E R2 bin around 3-4 years ago. Maybe only around 10%, yet in the same time period, they seem to have achieved ~70% increase in the lab.


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## Calina (May 11, 2011)

What is possible in the lab doesn't always make economic sense.


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## Cockatiel (May 11, 2011)

Hi !

I think this Baby is now the most effiency Light Source.
Appause to Cree.

Greetings


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## jtr1962 (May 11, 2011)

Calina said:


> What is possible in the lab doesn't always make economic sense.


It's more a matter of putting into the production line what is done in the lab. Yes, in some cases certain enhancements may make no sense at all. If something only increases efficiency by 1% but doubles the cost of the die, it really makes no sense economically. On the flip side, most of the efficiency enhancements lately involve things like patterned substrates, transparent electrodes, reduced resistance of the electrical path, etc. which are all relatively cost effective to incorporate into the production process. It's just a matter of figuring out how to do it without impacting yield. That where the 18 months to 2 years delay from lab to product comes in.


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## jtr1962 (May 11, 2011)

Cockatiel said:


> I think this Baby is now the most effiency Light Source.
> Appause to Cree.


Nichia hit 249 lm/W last year, albeit at 20 mA. I think they were using a different phosphor mix because their blue emitter was only about 81% efficient. Normally an 81% WPE blue emitter would translate into roughly 215-220 lm/W. They also reached 183 lm/W @ 350 mA with a high-power LED, again most likely with a more efficient phosphor which most likely sacrifices color rendering for efficacy. These facts make Cree's recent achievement all the more amazing. I'd love to see an efficiency versus current curve for this LED. If it behaves similarly to other recent highly-efficient LEDs like the XP-G, then efficiency probably peaks at close to 260 lm/W at around 80-100 mA (with a corresponding blue emitter WPE of over 90%).


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## saabluster (May 11, 2011)

Calina said:


> What is possible in the lab doesn't always make economic sense.


 
There was some very carefully worded signals from Cree in the release.

_"This R&D result features advanced aspects of the same technology used in Cree XLamp white LEDs."_

This is code for "expect to see these put in production".


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## videoman (May 11, 2011)

I'm buying Cree stocks tomorrow, I mean it !


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## HooNz (May 11, 2011)

That CRI thing explains alot , out here in Rural and since acquiring the LED torch i have noticed with my nightly walks that using the LED , somethings just become invisible at around 100m , some fence posts (old wood and silvery) , rusty things (rail-track steel as post supports) and certain coloured bushes , yet obviously with a old ican they are easily visible .
When one gets closer 50m or so they become more visible with the LED.

I just assumed it was wavelength , nearly a good guess imo. 

So with that , i certainly would think again about LED spotlights on a motorcycle , as at speed (value not mentioned :shakehead) , if a 10ft bit of rail line dropped from the sky vertically and landed in the middle of the lane 4ft deep on a dark country road (its possible :huh , by the time one noticed it one would be roadbait :naughty:and slightly terminated .


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## IMSabbel (May 13, 2011)

Have you considered to the possibility that your incan simply has better throw?


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## HooNz (May 13, 2011)

IMSabbel said:


> Have you considered to the possibility that your incan simply has better throw?


 
That would be stating the obvious! , the XR-E R2 throws past the Incan a 5D in distance , 270m or thereabouts , incan around the same but the brightness is lower, i'll assume you have read that the D11 was the culprit , but no , and just maybe you are not aware that colour rendition is not a trouble with LEDs depending if it was mission critical or not .


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## BrianGT (May 15, 2011)

Crazy how fast the R&D is going in the LED field. I can't imagine where this will be in a couple more years. Sounds like some day you will be able to light a whole house for less than the consumption of a 100W incandescent.


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## 2xTrinity (May 15, 2011)

HooNz said:


> That CRI thing explains alot , out here in Rural and since acquiring the LED torch i have noticed with my nightly walks that using the LED , somethings just become invisible at around 100m , some fence posts (old wood and silvery) , rusty things (rail-track steel as post supports) and certain coloured bushes , yet obviously with a old ican they are easily visible .
> When one gets closer 50m or so they become more visible with the LED.
> 
> I just assumed it was wavelength , nearly a good guess imo.
> ...


In my experience, this is mostly due to beam shape, not spectrum/wavelength. (Although going from cool white to neutral white for LED does make a large difference) Most LED lights for sale have a lot more intense spill, and much less intense center hotspot compared to incandescent lamps with the same number of lumens. This will make things in the foreground brighter (causing your eyes to adjust) and make things far away harder to see.

I tested two lights that had slimiar beam intensity pattern a few years back -- an ROP incan lamp (3400k tungsten) , and a Cree MC-E with aspheric (4200k neutral white), with similar beam patterns, I didn't perceive that the incan offered a huge advantage in terms of long-distance rendition. Comparing LED lights with reflectors however (and lots of spill), the incan is superior.



> Now with blue emitters not far off 90% efficiency, I think there's going to be more focus on the phosphor end. Either that, or improving the efficiencies of red and green to match blue. We can in theory approach 400 lm/W with decent CRI. We just can't do it with blue plus phosphor LEDs.


JTR -- completely agreed. I'm geuessing nearly all of the improvement with Cree's lab-prototypes, compared to what is on the market today, is due to changes in the phosphor layer.

With efficiencies on the order of 80% available for blue LEDs, I think it might be a good idea to start looking into schemes that separate the phosphor from the emitter, at least for applications in general light where diffusion is used. I think something like blue dice emitting light into a slab light guide (similar to what is used for LCD backlights), with phosphor distributed all over the surface, would eliminate problems of heat being localized in a tiny phosphor area. It would also be suitable for being mounted on a wall or ceiling and providing uniform light more efficiently (compared to using a "point-source" type LED with a reflector and diffuser and losing ~25% in the optics). 

Phosphors could also be replaced independently of the emitter, which should have longer lifetime.

Certainly lack of efficient green. I see this as a pretty fundamental materials problem, as there aren't reallt any semiconductor materials with a bandgap near thaat wavelength range. Green LED require very heavy doping concentrations and thus, more lattice defects/imperfections that lead to low efficiency. 

I suspect we will actually see >300 lm/W white light source (limit of blue + phospho) first in lasers, not in LEDs. Efficiency and overall output of fiber lasers has been increasing exponentially the last few years. Blue laser diodes are nearly as efficient as blue LED dice. 

Nonlinear optics phenomena like supercontinuum generation have been demonstrated in research literature, that can transform light from one wavelength to another without loss. I suspect we will eventually see coherent white light sources come out as a replacement for the ~$500 HID bulbs commonly used in projectors today. A ~10 watt white fiber laser could be split with a couple dichroic fiber couplers, then raster scanned to make a simple, compact, highly power-efficient projector.


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## zzonbi (May 15, 2011)

So what's the main trick behind this? Is it the ridged die, as with Nichia?

With Cree most of the time it's just a number and nothing else to these announcements. Their products are excellent though, but there again the improvement was mostly lm/$, less so lm/W and even less lm/mm2 (basically stagnant).


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## blasterman (May 15, 2011)

> I didn't perceive that the incan offered a huge advantage in terms of long-distance rendition. Comparing LED lights with reflectors however (and lots of spill), the incan is superior.



These discussions about incan -vs- LED are often so bad from a science perspective they usually aren't worth commenting on, but since you are doing a good job so far: If I put 5 watts of power in a state of the art LED source -vs- an incan source, the LED source is going to win in terms of photopic brightness by orders of magnitude. 5watts can easily produce over 500 OTF lumens of LED source, and at 100 meters even a cheap reflector can cause you to look away. 5watts produces trivial amounts of incan light, and anybody who says that the incan light would be brighter won't be taken seriously...other than maybe the incan forum here. 5 watts of 450nm LED source in a $1.00 chinese reflector can and will cause eye damage from tens of meters. Can't do that with incan.
If however it's a lumen -vs- lumen comparison, then the incan/halogen source often wins. Our eyes are most sensitive to far cyan / green in both scotopic/photopic ranges, which is where the legitimate lumen curve is weighted. In a *per lumen comparison*, an incan / halogen source is going to throw a lot more energy in the green spectrum than a cool-white LED. When you start lowering the CCT of the LED source the green component increases and this means better photopic vision. Given foliage is green, it's going to reflect better as well. So, the flashlight guys claiming they can see better at night with lower CCT LEDs -vs- cools have science on their side. Incan has an arguement, but only on a per lumen basis and -vs- higher CCT LED sources. Cree though at least is using 4500 CCT as a rough basis for new emitter comparisons, and for this they need some kudos.

It's typically amber though that kills efficiency in higher CRI emitter categories. We can assume the new technology being discussed here is likely in the 70-75 CRI range, but that's still pretty good. Bump it up to 80-85 CRI via increasing the typical amber component and you're still over 200 lumens per watt...theoretical.



> That where the 18 months to 2 years delay from lab to product comes in.


 
According to the graph posted above it's about double that.I'm only seeing a trickle of emitters over 110 lumen per watt at 4000-4500 CCT, and less in the higher CRI bin. The theoretical improvements in broader spectral efficiency are 'kewl', but only once they reach the production phase, and I'm a bit dissapointed you seem to be so excited about a press release with as much disclaimer at the end as substance. 



> I'm buying Cree stocks tomorrow, I mean it !


 
Exactly why they make these press releases. Might want to call your financial advisor first.


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## jtr1962 (May 15, 2011)

blasterman said:


> According to the graph posted above it's about double that.I'm only seeing a trickle of emitters over 110 lumen per watt at 4000-4500 CCT, and less in the higher CRI bin. The theoretical improvements in broader spectral efficiency are 'kewl', but only once they reach the production phase, and I'm a bit dissapointed you seem to be so excited about a press release with as much disclaimer at the end as substance.


I was looking at the 160 lm/W point, and then noticed the XM-L came out about 2 years after 161 lm/W was reached in the lab. Obviously warm and neutral lags cool by another 6 months to a year, sometimes even two.

As for being excited, I'm only excited insofar as the lab result proves 231 lm/W with a power LED is possible. I remember around here 7 or 8 years ago we were often speculating when, even if, LEDs would take over lighting. It wasn't a given that they would because nobody had surpassed even 50 lm/W in the lab. The situation could have paralled what happened with thermoelectrics in the early 1960s. Everyone at the time was saying once they exceed 50% of Carnot efficiency, or something similar, they would take over mechanical refrigeration. As we all know, that never happened. They just didn't find anything better than bismuth telluride. Thermoelectrics as a result remained mostly an expensive niche technology. Even now, the only reason they've become commonplace is because we've bought production costs way down. What comes off the assembly line today isn't a whole lot better than what we had when I was born. Now if on the other hand, someone somewhere had a lab device which at least proved greater efficiency was possible, there would have been a race to commercialize it (and incidentally there finally ARE greatly superior thermoelectric devices in the lab). That's basically what I get out of Cree's press releases. They tell me it's possible to build an LED of such and such efficiency. Once everyone knows it's possible, usually eventually someone will do it commercially.


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## MikeAusC (May 15, 2011)

jtr1962 said:


> . . . . An LED only heats up because it's less than 100% efficient. At 231 lumens per watt, I'd estimate you're getting at least two-thirds light and only one-third heat. . . . . .


 
My real-world tests at low current on the XM-L, rated at 100 lumens/watt, show that it puts out 70% as heat, leaving 30% as light. If the efficacy is improved 2.3 times, it would put out 69% as light, leaving 31% as heat, close to your estimate above.

We need to be cautious about all efficacy claims, because EVERY datasheet shows all Flux measurements carried out at 25 degC JUNCTION temperature. Unless you live in the Polar regions in winter, it's very unlikely your LED junction will be anywhere near 25 degC.


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## EngrPaul (May 15, 2011)

Good news! LED's will exceed CFL's to eliminate all that mercury and reduce electronics in the landfills.

Hopefully better emitters and better fixture ventilation converge to make total LED home lighting a common thing by the end of the decade..


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## Illum (May 15, 2011)

LEDAdd1ct, I have not seen a new LED that did not begin its development at 6500K. :thinking:


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## znomit (May 15, 2011)

MikeAusC said:


> We need to be cautious about all efficacy claims, because EVERY datasheet shows all Flux measurements carried out at 25 degC JUNCTION temperature. Unless you live in the Polar regions in winter, it's very unlikely your LED junction will be anywhere near 25 degC.


 
Recent cree datasheets are at 85 deg C.


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## MikeAusC (May 16, 2011)

Interesting ???

The earlier XM-L Datasheets I have (CLD-DS33 Rev 0) specify everything at 25 degC.

It looks like Cree will be the first in the industry to use a more realistic Junction temperature !


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## saabluster (May 16, 2011)

MikeAusC said:


> It looks like Cree will be the first in the industry to use a more realistic Junction temperature !


 Cree and Philips both annonounced the same day new products with binning at 85C. It does seem Cree was first by maybe a few hours or something not that that means anything. This definately is a good turn in practice.


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## HooNz (May 16, 2011)

2xTrinity said:


> In my experience, this is mostly due to beam shape, not spectrum/wavelength. (Although going from cool white to neutral white for LED does make a large difference) Most LED lights for sale have a lot more intense spill, and much less intense center hotspot compared to incandescent lamps with the same number of lumens. This will make things in the foreground brighter (causing your eyes to adjust) and make things far away harder to see.
> 
> I tested two lights that had slimiar beam intensity pattern a few years back -- an ROP incan lamp (3400k tungsten) , and a Cree MC-E with aspheric (4200k neutral white), with similar beam patterns, I didn't perceive that the incan offered a huge advantage in terms of long-distance rendition. Comparing LED lights with reflectors however (and lots of spill), the incan is superior.



Ok , i have a vertical rail-track post *100m* from the front door here , i think it used to be used as a support for a old telegraph pole back in the old days to fix a cable to it , its about 5 foot high with 2 pieces welded to support it also , the back ground beyond it is grass/scrub and the railway embankment 50m past it , i just tried again from the front door at 11pm clear dark night with the floody yet still good throw (to 80m past the target) XML T6 dropin to see if you were imagining it , i already know that target is there but as mentioned its invisible , but only if you know its there one can guess one see's it , then , after inserting the XR-E R2 dropin designed for throw which is very throwy (to 100+m past the target) and fairly limited spill i checked again to see if you were imagining it again  , and again if one did not know it was there one would not see it , then firing up the 5d with fairly weak batteries at that it showed up clear as a bell with no is it or is it not there's!

Those fence stumps/post are the same as mentioned (old gum wood)

I am not about ican/led better this or that , all i did was mention what i did.

A high CRI LED *yet* lower output with a more natural colour seems to be the go for my personal taste so far , i'll try them one day as that'll be cheaper than a Magcharger that seems to have just been released .


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## LEDAdd1ct (May 16, 2011)

Illum said:


> LEDAdd1ct, I have not seen a new LED that did not begin its development at 6500K. :thinking:



*scratches head*

I might be wrong. I always thought the first batch of LEDs was usually at a high color temperature (cool white) and not in the neutral range. So, when I saw that this lab LED/prototype was at 4500K, I thought that was really neat, and cause for excitement.

Is that wrong...?


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## deadrx7conv (May 16, 2011)

Lumens per watt is meaningless and lame manufacturer bragging if CCT and CRI aren't mentioned. 

Concerning LED vs incan, it could also be too much blinding glare/reflection from objects that are closer that overwhelms what little light is reflected from what you're looking at. I notice distant things that disappear or can't be distinguised while using an LED. I get plenty of throw from my LED flashlights but they are definitely lacking in providing the "real" light that is needed and can be used to notice or identify something in the distance. I can't tell if a wild animal down the driveway is a racoon, rabbit, cat, dog, fox, coyote... with most of my LED lights, or if a snake slithering by is the friendly or deadly type. Use the incan and you automatically can identify. This is one reason that I prefer my warm white keychain EDC QuarkMini123 over its brighter cool white sibling. I vote for CRI and CCT/K. Warmwhite isn't my preferred color but at least I can distinguish among and identify objects at night even if they aren't well lit. I'm not colorblind yet, or maybe I am and the low-CRI and overly too-high-CCT brings out and exaggerates that blindness. Give me high-CRI lumens/watt!

The LED manufacturers need to stop bragging about lumens/watt and start pushing "CRI Lumens"/Watt, or "CRI+CCT" lumens/Watt. I'm glad to see some LED manufacturers rating the lumens/watt at a given real-world temperature, along with those flashlight makers that know what ANSI is.


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## carl (May 22, 2011)

Cree 231 Lumen Per Watt LED Shatters LED Efficacy Records May 09, 2011

DURHAM, N.C. --(Business Wire)-- 
Cree (News - Alert), Inc. (NASDAQ: CREE), a market leader in LED lighting, reports another industry-best efficacy record of 231 lumens per watt for a white power LED. This result is a significant advance beyond Cree's previous industry record and further demonstrates how Cree's relentless innovation continues to push the boundaries of what is possible with LED lighting. 

Cree reports that the LED efficacy was measured at 231 lumens per watt using a single-die component at a correlated color temperature of 4500 K. Standard room temperature 350 mA testing was used to achieve the results. 

"It wasn't long ago when 200 lumens per watt was considered the theoretical maximum efficiency for a lighting-class LED. We broke that barrier in 2010, and have now achieved 231 lumens per watt," said John Edmond, Cree co-founder and director of advanced optoelectronics. "The innovation from our labs is the foundation for our industry-leading XLamp® LED family and an invention that continues our leadership of the LED lighting revolution." 

This R&D result features advanced aspects of the same technology used in Cree XLamp white LEDs. Cree believes higher-performance LEDs can enable new LED-based applicatons and drive down the solution cost of current LED-based designs. 

While this level of performance is not yet available in Cree's production LEDs, Cree continues to lead the industry with the broadest family of high-performance LEDs.


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## HooNz (May 22, 2011)

carl said:


> Cree 231 Lumen Per Watt LED Shatters LED Efficacy Records May 09, 2011
> 
> DURHAM, N.C. --(Business Wire)--
> Cree (News - Alert), Inc. (NASDAQ: CREE), a market leader in LED lighting, reports another industry-best efficacy record of 231 lumens per watt for a white power LED. This result is a significant advance beyond Cree's previous industry record and further demonstrates how Cree's relentless innovation continues to push the boundaries of what is possible with LED lighting.
> ...


 
I see a few thing here , in the first sentence , it is only for KKK members .
2nd , Effiancy , i would have used Efficiency as i had to look the other one up and learnt absolutely nothing .
3rd , by the time it is out it'll be superceded going by the last sentence .
imo


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