The circuit shown, with the printed circuit board, was found in an article in the June 1990 issue of Radio Electronics magazine. Integrated circuits must be equipped with heat sinks.
This circuit is from an English magazine of 1977. The circuit is still current, just using BC547...
This circuit was obtained in an old Elektor. It is a reference, since the integrated products of the...
This circuit was found in a European technical documentation from 1991. It is a circuit that must...