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.
In the figure we have one of the channels and the source of a good stereo amplifier of 20 W per...
This circuit is based on the voltage drop of the diodes in conduction, in the order of 1.6 to 1.7...
Texas Instruments Type D flipflops N74LVC1G79 and SN74LVC1G179-Q1 for operation from 1.65 to 5.5V...