This circuit was found in a 1967 RCA documentation. The components are of the time. The circuit limits the current to 50 mA when the battery is fully charged.
This circuit, found in 2002 documentation, triggers LEDs when a phone call is received. The LEDs...
This simple version of a function generator with the XR2206 was found in the May 1977 issue of...
A pulse triggers this 800 Hz horn for a time determined by capacitor C1. Powered by 5 V the...