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.
In the figure we present a circuit of a microphone signal conditioner using the SSM2167 integrated...
This transmitter emits signals in the FM range, reaching a few meters away. The modulation...
This circuit was obtained in an English publication of 1993. It is an amplifier for...