Hello Js

JS>>Theoretically I could use very small value resistors as long as their ratio worked out correctly, right? How about two low-resistance trim pots to create the perfect 1.404 ratio?<<

Well... not really...

Current = Voltage divided by resistance.
c= v/r

if your e=12, and your r = 1, your current is equivalent to

c=12/1 = 12 amps. That will drain most batteries in nothing flat.

If your Resistance is very high... (lets say 1 million ohmes)

c= 12/1,000,000

c=.000012 Which is very little current. batteries will last almost forever.

So, you choose the Resistance that is the highest, that will work reliably with your PIC. I have never "tested" the high end range of the PIC (nor the low end). But since you are using this on a airplane... go for higher resistance. The more resistance the less current, and that means longer battery life.

Now my disclaimer... I used "C" for current, and v for voltage... Usually it is "I"...for current and E for voltage in this equation...but live goes on...<g>

Dwayne