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.
This circuit was found in Italian magazine (1988), but can be mounted with ease even with the...
This circuit was found in an American 1980s documentation. The components are current but most...
This circuit of old American documentation (1965) can be applied to any transistor. | Clique na...