This circuit was found in a 1980s American documentation. The circuit is based on integrated CMOS 4001 that are common today. The load is a relay according to the power supply from 6 to 12 V.
This circuit is powered by 1.5 V and has a long lifespan as it consumes only 320 uA. The circuit is...
This is a very simple version in which we simply fit the jacks, plugs with red and green LEDs,...
Taken from a 1956 Raytheon transistor manual, this circuit uses varistors to obtain modulation of a signal...