Archive of the former Yahoo!Groups mailing list: ComputerVoltageSources

Re: matching resistors, will the following procedure work?

Ingredients:
1 precision voltage reference
1 amplifier
1 voltmeter
Resistors to be matched (RTBM)

Feed a small, precisely regulated signal through a voltage divider
made from an RTBM and some other resistor (the "constant"). Feed the
divider's output through the amplifier. Measure the output. Repeat as needed.

The idea, obviously, is to amplify the differences between the RTBM
so that the voltmeter can register those differences. Concerns would
include temperature stability, power supply stability, etc...

So, this may not be good enough for a NASA guidance system, but will
it suffice for this DIY project? As John Lofflink said, we need only
be concerned with relative accuracy.
--
john