This simple transistor tester was found in a Japanese magazine in 1967. It tests general purpose transistors of both the NPN and PNP type and is powered by 4 batteries (6 V).
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...