This circuit was found in the July 1992 Radio Electronics magazine. Sensitivity adjustment is made at R6. Supply voltage is matched to that of the relay.
The components used in this 80's circuit are not common today. The circuit is very sensitive and must...
The circuit shown is for testing both signal diodes (low current) and rectifiers (high current). The...
Connected to the output of an audio amplifier or radio this circuit indicates the level of the...