Stealth Pilot wrote:
On Thu, 07 Jan 2010 15:39:13 -0500, Charlie Smith
wrote:

Jim,

From info I have located on the internet, I have cobbled together a
circuit diagram for illuminating my instrument panel using LED's. I was
wondering if I emailed you a copy, would you would be kind enough to
take a peek at the circuit and see if I missed anything? Electronics
isn't my expertise but I enjoy it all the same.

Thanks in advance,
Charlie Smith

charlie, assuming that you are using a 12 volt bus, all you need to do
to use an LED is put a 680ohm resistor in series with it.
so if you had an instrument that was lit by a small tungsten globe, in
theory, all you need to do is take out the lamp holder and wire in the
led and the resistor in its place. the led should then work with the
original switching.
you need to have a resistor in series with each LED. so if you use a
number of LED's in the panel each must have a resistor in series with
it.
simple enough isnt it.

Stealth Pilot

No, its more complicated than that. I'm building the instrument panel
from scratch with 20 LED's. I have put together a PWM dimmer circuit
that has a built in 5V linear regulator. That way, if the battery
starts to die, I have panel lights down to about 7V on the battery. I
just wanted Jim to look it over and make sure I didn't miss something
obvious. I am quite capable of some bone-head mistakes. I've
bread-boarded the circuit and it works fine (with one LED). But that's
different than flying with it.

Thanks,
Charlie