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 circuit is from an English magazine of 1977. The circuit is still current, just using BC547...
This circuit was obtained in an old Elektor. It is a reference, since the integrated products of the...
This circuit was found in a European technical documentation from 1991. It is a circuit that must...