This circuit triggers an alarm when the mains power is cut off. The circuit was found in the July 1990 issue of Radio Electronics magazine.
This 50% active cycle TTL clock generates signals from 4 to 20 Hz. Its power must be supplied with 5 V...
This bench circuit with no active components appeared in the August 1958 Radio Electronics...
This crystal-controlled circuit was obtained from a 1980s documentation. The power supply should be 5...