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.
Found in Radio Electronics from the 90s, this circuit uses a thermistor as a sensor that can have...
This circuit is from a 1976 Motorola power semiconductor manual. In it we have the optical...
Found in American documentation from the 90s, this circuit converts 28 V to 155 V with a frequency of...