Join Date: Jan 2011
Location: Oklahoma City, OK
On the importance of a heatsink
I previously have posted that I thought we were using excessive heatsinks on some of these LED builds. After some testing, I can confirm that I was wrong.
I have built 2 LED rigs, and I can confirm that heatsinks matter quite a lot.
The first rig I built is constructed of XR-E Cree LEDs. I used simple L-channel aluminum. It worked and I had no failure, but to be truthful I believe that the LEDs lost some considerable lumens during usage. This might also be the result of the corrosion caused by having these inside of a closed hood.
I built another rig using Bridgelux LEDs and the same L-stock. I figured that they would work just as well. I was wrong. I did an initial test of a few hours, and my heat was staying around 50C. I assumed that this would be acceptable, since everything I found had the Bridgelux LEDs rated up to 150C(at the diode). I was wrong. After leaving them on for 8 hours, I found all of my LEDs were burned out and operating at a very dim glow.
Unless anyone can think of anything else that could have happened, I am completely stumped.