This General Electric circuit was found in a 1964 documentation. The circuit triggers a relay when the sensor is activated. Trigger adjustment is done in a trimpot.
This circuit provides a power of the order of 2 W, characterized by high performance. The output...
Suggested by an old Popular Electronics, this circuit is based on an uncommon integrated today,...
This small preamp for low impedance microphones was found in a Popular Electronics from November 1968....