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.
This circuit is from an Electronics World of 1967. The circuit slows down the activation of a...
This metal detector circuit uses an AM radio as an indicator. The radio is placed off-station and tuned...
In the figure we have a sensor circuit that makes use of common transistors and a photo diode as...