Michael Grass wrote:
> ...
> 1 Electrolytic capacitor of 1000 uF min.40V
> 1 Voltage regulator from the 7805 family...
It won't do any harm, but a big 1000uf/40V cap will not accomplish anything,
since
you have a real monster filter capacitor already in the form of the airplane's
battery. However, National Semiconductor's application notes for the 7805
say you _do_ need a .22 or .33uf cap here, where the regulator is some distance
---From the input filter (here the battery), and for the implied purpose, a
small
value cap does the better job of it than 1000uf.
> 1 Electrolytic capacitor of 100 uF min.40V
A cap that size on the output can be harmful per NS, but the unknown here is the
effect of high-freq alternator noise on the input (vs 60Hz AC) and motor noise
on the output. I'd thus eliminate this added cap on the output and help protect
the 7805 with a rectifier diode (1N400x) across input/output, with the banded
end toward the input.
Regards,
Fred F.
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