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 1998 circuit controls the volume in a stereo system by touching switches. The circuit is for...
A 25 mVpp applied to the input of this circuit produces in the output a 1 Vpp signal. The...
The basic integrated circuits of this 1988 multimeter are no longer very common today, but if...