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.
This circuit, which in our times would be called a shield, can also be used with other loads. The...
This converter converts signals from the 50 MHz band to the AM band, making it possible to receive...
Other operational amplifiers series, such as the MC34072, MC34074, MC35071, MC35072, MC35074 d...