I have two high voltage nodes which I need to measure the differential voltage between. What I am thinking at the moment is the following...
1 - Use voltage dividers to probe the voltage at 1/1000, thus having a differential voltage of 0.500Vdc and 0.501Vdc.
2 - Use an operational amplifier with a gain of 1000 to obtain the original differential signal.
3 - Use the 1Vdc differential voltage with my analog to digital converter (this part is extra, the first two are where my roadblock lies.)
The problem I have with this approach however is the slight error in the resistors and other small components will affect the accuracy of the final reading. Even using resistors with 0.5% tolerance and coupled resistors (is this the proper name for them?) may not be enough.
Is there a more traditional way of obtaining the differential voltage between high voltage lines?