We found this circuit in an American 1980s documentation. The circuit uses a piezoelectric transducer unusual in our day. The transistor is general purpose type.
Taken from the 1982 SGS manual on integrated circuits, this preamplifier was used in commercial...
This circuit was obtained from English documentation on FETs. The JFET can be any general purpose and...
This power inverter circuit was found in Radio Electronics magazine from December 1959....