2 things , which led is this ,did cree ever put it out into production

[qip]

saw this on wiki

"The company holds the record for the most efficient White Led with a prototype that can produce 130 lumens per watt when 20mA of current is applied, nearly 10 times what an incandescent (normal) light bulb can produce"


or is that just wiki being wiki with some fake info


number 2 if you look theres an external link to cpf page of cree flashlights

 

[R33E8]

It is possible to get 130lm/w at such a low current but it wouldn't be worth... I think you would get about 7-8 lumens out of it at that current. The record part just needs to be updated.. Osram now has the highest efficacy white led prototype at 136lm/w at 350mA. http://www.candlepowerforums.com/vb/showthread.php?t=203330
The efficacy at lower current is over 150lm/w..

Oh, and the LED they might be referring to should be the Xlamp series...

 

[saabluster]

That is old info. Needs updating as R33E8 mentions. It is interesting however what can be achieved with currently available LEDs. Check out this post and you will see the XR-E R2 can get up to about 145 lm/W at about 50mA. Pretty amazing.

saw this on wiki

"The company holds the record for the most efficient White Led with a prototype that can produce 130 lumens per watt when 20mA of current is applied, nearly 10 times what an incandescent (normal) light bulb can produce"


or is that just wiki being wiki with some fake info


number 2 if you look theres an external link to cpf page of cree flashlights

 

[Marduke]

One reason these "record breaking" LED's are only ever prototypes is because they often degrade very quickly, sometimes within a matter of hours of use. They are therefore not practical for any real application, and only more robust designs which can withstand many (often tens of)thousands of hours of operations are produced.

 

[qip]

???? what am i missing , how does it get that much on 20-50ma when at 350ma it gets 100+ ....looking at the graph it starts out high but how , on what voltage or what not...usually i see lumens stated like 100 @350ma etc ...this is saying 100@20ma im confused right now


and then why havent we seen lights using only 20ma on high mode for the 100 lumens that would be great runtime ?

 

[Marduke]

I think you're confusing lm/w (efficiency) and lm @ 350mA (flux at a standard drive current). Just because a LED has a maximum efficiency of say 150 lm/w when drived at 20mA for example, when you actually drive it at 1watt, efficiency goes down to maybe 120 lm/w.


There are lots of lights which use the maximum point of efficiency for LED's such as Cree by driving them at about 20mA. That is actually the reason the low mode of Fenix is what it is, and why they don't make the low mode any lower. In current regulation, if they drove it any lower, efficiency would actually go down. 20mA is kind of a sweet spot, and you have to use PWM to get any lower and not loose efficiency.

 

[Oznog]

Also they're selecting the highest bins there.
When you have a Rebel LED binning system that produces 40-100 lumens at 350mA and a Vf of 2.55v-3.99v. So technically you may have 112 lumen/watt LEDs there already if you can find a Vf that low in the high lumen range. But the Vf is more realistically 3.15v and if you look at the Rebel spec sheet they actually describe that mfg will produce a gaussian distribution (bell curve) which places most of the white production at around the 80 lumen (and 80 lumens/watt) bin.

It's not really important what you can find as the "best" one in the batch, but rather what's actually going to be produced in significant volume and be purchaseable.