On Mon, 11 Jan 2010 21:06:32 -0500, Charlie Smith
wrote:

I have cobbled together a circuit from available internet sources to
illuminate a homebuilt aircraft instrument panel. I was wondering if
those qualified in this group would mind reviewing the schematic and
making constructive commentary. I'd like this thing to be reliable and
not cause a host of other electronic gremlins. Just keep in mind, I'm a
chemist, not an electronics professional. But, I do learn quickly.


Thanks.
Charlie Smith

It's not very efficient. You could put the LEDs in series clusters and
run the substrings from a somewhat higher voltage.

A mosfet would be nice, instead of the antique 3055.

Come to think about it, PWM isn't any more efficient here than linear
regulation. A variable-voltage regulator, LM317 sort of thing with a
pot, could replace the 555 and all that stuff. Much simpler.

John