Found in a 1980s documentation, this amplifier uses an integrated circuit that is not easy to obtain now as it is of the era. The circuit is intended for FI ceramic filter circuits.
Found in an American documentation from 1969, this circuit operates at a frequency determined by the...
This source, obtained in the 1982 SGS manual, has pre-regulation and provides a current according to...
This circuit was found in the December 1992 issue of Radio Electronics magazine. The current is a...