This circuit was obtained from 1967 documentation. It uses a sensor to determine the trigger point. The components are of the time, difficulty to obtain these days.
Found in the July 1968 Supertena Bulletin of a Popular Electronics, this receiver makes use of the...
This switching source was obtained in a 1976 National Semiconductor manual. For the indicated...
This configuration appears several times on this site. The circuit can generate a 100 kHz or other...