Based on a CA3059 zero-cross switch, this circuit was found in the July 1995 Electronics Now magazine. The circuit is not isolated from the mains.
Found in American documentation from the 90s, this circuit can use a BC548 instead of the original...
This circuit acts on the dynamic range of an audio signal, which can be useful for recording,...
This circuit doubles the frequency of a signal using a varicap. In this case, the input is 28 MHz,...