Power cord leakage detection and protection circuit

A power cord leakage detection and protection circuit is characterized by including a live wire, a neutral wire and a tripping coil, wherein a controlled switch controlled by the tripping coil is respectively provided on the live wire and the neutral wire;

• a shielded wire is respectively provided outside the live wire and the neutral wire;
• tail ends of the two shielded wires are connected;
• a shielded wire detection circuit respectively connected to head ends of the two shielded wires is provided between the live wire and the neutral wire for detecting whether the shielded wire is cracked;
• and the shielded wire detection circuit is connected with a control circuit for controlling the tripping coil to disconnect the controlled switch when the shielded wire is detected to be cracked;
• wherein the shielded wire detection circuit includes a switch tube Q2, wherein a collector electrode of the switch tube Q2 is respectively connected to one end of a resistor R10 and a negative terminal of a diode D3;
• a base electrode of the switch tube Q2 is respectively connected to the other end of the resistor R10 and a head end of the shielded wire of the live wire via a resistor R11;
• an emitter electrode of the switch tube Q2 is respectively connected to a pin 1 of a rectifier bridge DB1 and the head end of the shielded wire of the live wire via a resistor R12;
• a positive terminal of the diode D3 is respectively connected to the live wire and one end of a resistor R7;
• the other end of the resistor R7 is respectively connected to a pin 3 of the rectifier bridge DB1 and one end of a resistor R6, and the other end of the resistor R6 is connected to the neutral wire;
• a pin 2 of the rectifier bridge DB1 is respectively connected to one end of a capacitor C2, one end of the resistor R9 and a pin 1 of a photoelectric coupler U1;
• a pin 4 of the rectifier bridge DB1 is respectively connected to the other end of the capacitor C2, the other end of the resistor R9 and a pin 2 of the photoelectric coupler U1;
• and pins 3 and 4 of the photoelectric coupler U1 are respectively connected to the control circuit.