tech article - LED droop

jerry i h

Enlightened
Joined
Jul 26, 2007
Messages
268
Location
Berkeley, CA
http://spectrum.ieee.org/semiconductors/optoelectronics/the-leds-dark-secret/0
http://www.scribd.com/doc/21615915/IEEE-Spectrum-Magazine-August-2009

The droop in the article is not about the sag in lumens from a poorly heat-sinked Lux. CFL has efficiency of 100 lm/watt, LED is 250, but only at low power levels. Crank up the power, and the efficiency droops to only 100. The article reviews current research into this. They say that LED should be capable of 300. So, a 7 watt LED at 300 lm/watt will give the same light as a 100 watt incan, as opposed to the 23 watts required by CFL. I found the article to be quite interesting.
 
Last edited:

Illum

Flashaholic
Joined
Apr 29, 2006
Messages
13,053
Location
Central Florida, USA
led efficiency has always been the highest in low current applications, why do many expect that efficiency value to apply at a higher current?

If this was taking place as the light in your fridge maybe...but not in a Tj = 25C setting
 
Top