Stupid resistor tricks
February 4, 2007
Why am I doing this? If the “simple” synchronized rectifier doesn’t work, I think I can build one using an LM158 (low-voltage op-amp) together with a pair of precision voltage dividers (to divide inputs at or outside the supply voltages, into valid inputs for the op-amp). I’ve done this trick once before building a light-board, where I needed 24 sets of 3 matched resistors. For that, I just took 100 resistors, measured them, tossed out the outliers, binned and sorted the rest, and then just took them three at a time starting at one end of the sort. The resistors seem to stay similar over time.