Circuit as shown, with a touch of a finger when the metal sheet S, N neon tube light, since N and photoresistor RG constitute optocouplers make RG resistance becomes smaller, s
o the TRIAC VS because sufficient trigger current lead pass, it was electric socket load CZ on working. At the same time, 220V AC voltage through the CZ bulk capacitors C2, the diode VD1 and VD2 rectifier, regulator VDW regulator, filter capacitor C1 obtained by the DC voltage applied to the resistor R2 VS the gate, even if S has left finger touch, VS remains turned on, so that the load connected to the CZ normal power work. When power is restored after power outage, because VS has not been enough to trigger current, it is not turned on, the load on the CZ is powered off. Only CZ retouches to make the load on the power. When not connected to the load circuit, the socket itself has little power (about 0.5W). Socket load capacity of up to 500W. The circuit also has a feature: when there is no load on the socket, even though the touch of S, the socket is not live.Component selection: Choose a neon tube N ordinary neon tubes, photoresistor RG choose MG-45 models. VDW select regulator for the 12V zener diode. Resistor selection (1/4) Ws. Other components shown in FIG.