This reminds me of the circuit used by some folks to match transistors at home. In this case, it utilizes a form of wheatstone bridge with a potentiometer to de

This reminds me of the circuit used by some folks to match transistors at home. In this case, it utilizes a form of wheatstone bridge with a potentiometer to deal with non-matching resistors to level out the test rig (source of the circuit in question: https://www.youtube.com/watch?v=t--0fCMzfIo https://www.youtube.com/watch?v=t--0fCMzfIo ).