How do you predict light output from a LuxIII LED?
I know there is lots of discussion about this, but I don't quite follow, especially with the temperature part.
I start with the data sheet for the part, say LuxIII red-orange, which is rated 190 lumens at 1400 mA. But I don't want to use 1400 mA, I want to use maybe 1000 mA. So I look on page 12 of Lumileds' DS45 publication and find that "Relative Luminous Flux" for 1000 mA is 75%.
Now I am down to 0.75*190 = 140 lumens.
What about temperature? This is going to go in an aluminum flashlight. How do I estimate the effects of temperature?
I have read about all these calculations, but I think I just need to be walked through them with to understand.
Scott
I know there is lots of discussion about this, but I don't quite follow, especially with the temperature part.
I start with the data sheet for the part, say LuxIII red-orange, which is rated 190 lumens at 1400 mA. But I don't want to use 1400 mA, I want to use maybe 1000 mA. So I look on page 12 of Lumileds' DS45 publication and find that "Relative Luminous Flux" for 1000 mA is 75%.
Now I am down to 0.75*190 = 140 lumens.
What about temperature? This is going to go in an aluminum flashlight. How do I estimate the effects of temperature?
I have read about all these calculations, but I think I just need to be walked through them with to understand.
Scott
