This circuit is from an April 1991 Radio Electronics magazine. The circuit uses power MOSFETs and an integrated circuit from that time.
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...