This circuit was obtained from a Radio Electronics issue from January 1989. The indicator is a ceramic transducer, and the frequency of the emitted sound is given by C3.
This circuit provides a power of the order of 2 W, characterized by high performance. The output...
This 12 V to 110 V inverter with 100 W was found in a 1977 Signetics manual. The transformer must...
The gain of this amplifier is given by the components indicated in the formulas next to the...