This circuit was found in the February 1999 issue of Electronics Now magazine. The circuit consists of a timer that triggers a visual and audible starting device.
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...