The purpose of this circuit is to monitor the output voltage of a power supply. The under and over voltage indicator was found in the August 1991 Radio Electronics magazine.
This version of the circuit is from 2000, using a source of negative voltage that allows to obtain...
This somewhat complex circuit was found in the May 1984 issue of Radio Electronics magazine. The...
This basic circuit is from an old documentation. The relay must be 50 mA maximum and must have a...