This simple continuity tester consists of an oscillator found in the 1983 Electronics Experimenter Special projects magazine. The circuit is powered by a single battery.
This interesting circuit measures the distortion of the sinusoidal voltage of the power grid. We...
The operational amplifier used in this old application is not common today, but more modern...
Used in 1950s CW receivers, this type of circuit used germanium transistors. The circuit has...