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.
Found in a 1991 publication this circuit can be assembled with more modern components. We can use...
We found this circuit in a 1987 documentation. Its purpose is to turn on a garage light using the...
This is the circuit of a turntable from the 1970s. We found it in a repair article in the December...