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> I have also been toying about building a "black Box" to monitor
things. Besides the fuel level monitor, outside temp, data from EMC2 and
such. I can program it but building the components is the challenging
stuff and that is why it interests me. As i feed the airplane voltage into
my application, I divide the current by 1/3 so that I can feed my microchip
ADC. In my prototype, I have been using 1M resistors to do the
division. Does it matter on the size? My thinking is, since I only
want to voltage, the higher the better.
>
> Bob K
Bob,
Why not use a little 3 leg voltage regulator, no worry
about resistors heating or enough current to the ADC; grant it that an ADC draws
microamps. Will help keep out voltage spikes that can damage an
ADC. Then you can run other devices off the same regulator. The
radio shack ones have a schematic on the package. Can't go
wrong.
Wendell
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