This circuit was found in the November 1992 issue of Radio Electronics magazine. The circuit has an amplification stage for the relay. The relay is rated at 12 V.
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...