(Jeff Peterson) wrote in message . com...
the white 5 watt luxeons have 6.5v forward voltage at 100 ma, rising
to 7.5 v at 1 amp. so you cant put these in series if you have a 14
volt system.

Crud, thats the worse case, oh well. Are the white leds the most
efficient? If you can use red, you might be better off. I think
those guys make white by hitting a phosphor suspended in the epoxy
encapsulant with UV which emits photons in a broader but less
energetic range. There has got to be some conversion loss.

I was talking with a buddy that makes big LED signs and we realized
that the rated life of LEDs is at the half power point. So if you
expect the full 100,000 hr life, you need to start off with an array
that exceeds the spec by 2x at time zero. But come to think of it,
that will never happen on a GA aircraft.




a bypass capacitor or emi filter at the circuit should eliminate emi
due to the rapid switching of the FET. i think this is a better
solution than
slowing the swtich.

i will try to post the circuit later this week.

-Jeff