This simple circuit to monitor the frequency of the power grid uses an analog indicator. The adjustment trimpot can be 4k7 and the indicator is 100 mA full scale.
This circuit provides two slightly different audio signal outputs from a monophonic audio signal, so...
This detector is from the 1990 Motorola Dataar Databook, but can be adapted to work with more...
This traditional configuration of astable was found in a 1965 documentation. Transistors can be...