Voltage protection circuit

The utility model discloses a voltage protection circuit, including transformer T, rectifier bridge Q, electric capacity C1, potentiometre RP1, potentiometre RP2, chip U1 and bidirectional thyristor VS, 220V alternating current one end is connected respectively to transformer T coil L1 one end, resistance R6 and bidirectional thyristor VS's the T1 utmost point, the 220V alternating current other end and load RL are connected respectively to the transformer T coil L1 other end, electric capacity C3 is connected respectively to the load RL other end, bidirectional thyristor VS's the T2 utmost point, electric capacity C4, chip U1 pin 1, electric capacity C2, triode VT1 projecting pole, potentiometre RP2, potentiometre RP1 gleitbretter, potentiometre RP1, potentiometre RP1 gleitbretter, electric capacity C1 and rectifier bridge Q pin 4. The utility model discloses voltage protection circuit circuit structure is simple, has excessive pressure and undervoltage protection function, and is with low costs, especially adapted using widely.