Thermocouple

The matched application of the thermocouple and magnet unit makes up of the protection device for ensuring the flameout safety of the burning appliance. Thermocouple is a sensing element that may provide micro-power. The magnet unit is a control element. When its top end is heated by flame, thermo-electrical potential is generated by temperature difference between the cold and hot ends and a closed loop current is formed. The solenold valve under the combined action of outside force and magnetic field actuation is in the attracted state and the passage of fuel gas is open. When the flame is out, the temperature at the top end of the thermocouple is lowered, and the thermo-electrical potential and current gradually reduce. The magnet unit resets under the action of compressed spring and the passage of fuel gas is closed. Thus the safety protection function is achieved.