This control circuit or reversible contactor was found in a 1967 General Electric manual. The triacs must be in accordance with the power of the controlled load.
This oscillator takes advantage of the 2000 ohms headphone inductance as the oscillator circuit coil....
This 1/2 hertz high selectivity filter was found in the December 1990 issue of Radio Electronics...
This circuit applies to an old dial phone by detecting light pulses in the dial. The circuit is...