binned luxeon III

I'm confused about the bins on Luxeons III's. For example, an "S" bin is rated at 60-72 lumens and "U" bin is 100+. Do both produce the same amount of light at 3 watts? Or, does the "U" run more effcient and actually produce more light at 3 watts? It's hard for me to belive the latter cause that would be some 37 lumens/watt!!!!!!
If this is the case where can I get "u" binned luxeons?


Thanks in advance

thus, a luxeon I would produce 45lm/watt.

Well, at the same current the U-bin will put out more light. Assuming both leds have the same VF, then the U-bin will be more efficient since it's making more light.

Now say you have a SX0H and a UX0N. Taking the low end of ratings of the bins on both flux and Vf, and at 700ma we come up with:
SX0H 51.7 lumens / 2.121 watts = 24 lm/watt
UX0N 87.4 lumens / 2.961 watts = 30 lm/watt

So in an extreme case of low Vf for the S bin, and extremly high Vf for the U bin, the U-bin still wins for effecinecy. A UxxH would be super duper efficeint. As the Vf relates to power in, and the U-flux relates to light out.

Check out this thread too BTW:
http://candlepowerforums.com/vb/showthread.php?t=96915

Isaac, thanks for the info!

No problem!

Also, there has been much discussion of the effeciency of Lux IIIs run at lower current levels for less brightness, but greater effeciency. After this post, I'll dig up McGizmo's post on effeciency of different Luxeon-class LEDs. VERY interesting reading.

From what I understand, you can further 'group' Lux Is with Lux IIIs as follows:

Lux III U bins are similar to Lux I S bins
Lux III T bins are similar to Lux I R bins
Lux III S bins are similar to Lux I Q bins

The Lux Is and Lux IIIs are basically made the same way, but biased or binned differently, based on what, I'm not 100% sure. That is to say, if you wired an R-bin Lux I up with a constant current regulator at 350ma you should expect VERY similar results as a T-binned Lux III at 350ma. The thing I'm not completely sure on is how exactly they determine which they will bin as Lux Is and which they will bin as Lux IIIs.

Here's McGizmo's excellent post:

https://www.candlepowerforums.com/threads/100228