G must be 1....... which means r1/r2 must be the same value, preferably with 1% or better tolerance
True, because you want to maintain the same values as before to the fuel cluster...just inverted. But to decide what values to choose for R1=R2, you have to measure the input signal from the fuel sender to see with what values you have to deal with on the op-amp. You don't want to blow the op-amp with too high current I-in
Edited by kilevox, 04 January 2008 - 10:30 PM.