This commercial circuit is from a Japanese magazine from 1967. It uses germanium transistors, and the coil can be made with 80 to 100 turns of fine enameled wire on a ferrite rod.
This is a slightly different configuration of full-wave power control than we found in an old...
This 1-transistor timer was published in Radio Electronics magazine in December 1960. The circuit has...
This type of circuit is widely used in old cassette recorders and tape players, regulating the...