This circuit turns off a relay after a time determined by C1. The circuit was found in the December 1974 Radio Electronics magazine. The relay is rated according to the supply voltage.
This adjustable direct current source circuit uses a triac operating as a variac. The circuit is...
With the precision given by the crystal this circuit provides signals of several frequencies for the...
This amplifier allows you to recover recorded tapes from a tape player that has the mechanism in...