We found this circuit in the 1983 Radio Electronics Special projects magazine. The components are common, and the circuit drives a relay. The power supply must be isolated.
The TAA865 integrated circuit used in this 1986 project is no longer common today. The circuit is a...
) These two circuits were obtained in a 1977 Radio Handbook. The transistors are from that time,...
The circuit shown is from the Motorola Linear Databook of 1990. It is based on the Motorola T...