Bimetal thermostat is normally closed and normally open type, their working principle is the same, but the work is the opposite. Bimetal sudden jump thermostat is a temperature after the bimetal as a thermal responsive components , When the electrical heat generated by the transfer to the bimetallic disc to reach the operating temperature bimetal rapid movement through the mechanism of action, the contact open or closed; when the temperature dropped to set the reset temperature, the bimetal quickly return to its original state , The contact is closed or disconnected, to achieve the purpose of connecting or disconnecting the circuit, thereby controlling the circuit.