This is the circuit of an automotive voltage regulator from the 1970s. The circuit is entirely electromechanical based on the closing of a relay contacts according to the voltage.
The presented circuit uses a PNP transistor, which can be the BC558. Observe the polarity of the...
This circuit was found in the May 1983 issue of Radio Electronics magazine. The SSM7046 integrated...
This mechanical reverberator circuit for guitar was found in the February 1970 issue of Radio...