Me again!
I've had the flashing landing light deployed in my airplane since this spring, and it seems to be working OK... but, as winter is coming, and I'll have time on my hands, I'd like to think about improvements.
I published an instructable on my implementation here:
http://www.instructables.com/id/LED-Landing-Light-for-Experimental-Aircraft/
As winter is coming, and I'll have time on my hands, I'm starting to think about the next generation of this setup. My questions to the forum are:
- There are nowadays many "off the shelf" LED based aircraft strobe systems. The ones I've seen are incredibly bright, but don't have much circuitry at all, especially the big, bulky current limiters that I've got, and certainly don't seem to generate much heat. What gives?
What are most manufacturers doing for flashing current limiters?
- I'm using 10W CREEs, with either 7 or 9 in parallel - i.e., in theory, I can drive it with between 70 and 90 watts, or between 21 to 27 amps of current. The linear regulator I'm using (an LM338) maxes out at 5 amps.
How can I increase the current to get more brightness?
and
- I'm flashing these CREEs with 5 x 100ms pulses / second. The pulses are in a rapid burst: flashflashflashflashflash .... pause ... flashflashflashflashflash. One idea that's crossed my mind is to just, gulp, eliminate the current limiter and just plain flash 'em. My thinking is that what really kills the LEDs in an overcurrent situation is heat, and that because my average current, or average power, is low due to the flashing, and also because of the inherent current limiting effect of the flash circuit and all the wiring, the instantaneous power will be far less than the average power, and so the heat may not be an issue.
Is just flashing the LEDs and hoping I don't fry them just plain dumb?
I'd be grateful for any input...
in net, how are the other guys doing this???
THANKS!
Dave