This circuit uses the SQ3524, a switching integrated circuit. The circuit was found in the April 1991 issue of Radio Electronics magazine.
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...