Thanks
The color is red, 660nm. Here is the part.
http://www.ebay.com/itm/10-pcs-3W-H...773?pt=LH_DefaultDomain_0&hash=item56581e3b7d
I guess I can just run them at a derated value, but I will only be using them about 1 hr/day so not sure if I need to do that. I need about a 3 year life out of it...so about 1,000 hours. The problem is which of the 3 options should I consider?
1) If it is at the wrong voltage, will it even turn on? I can get them to turn on in the specified voltage range.
2) Not sure how to determine this, if even possible.
3) I suspect they could run at a higher current...but what if one uses a LED constant current driver? I suppose you are stuck. Not much wiggle room for V*I it would seem unless I am wrong about option 1.
As far as heatsinks go, you are right. They will not have air flowing over them, but they will be in the open (no housing). So far, they get pretty warm to the touch. After about 5 seconds, it becomes uncomfortable to touch. I really don't know what the junction temperature should be though :/ I can detach the heatsink and measure it, but what is the proper value? I suppose if it making good contact, it shouldn't be too much higher than the heatsink itself.