Switch circuit having protection function to interrupt input of control signal

A switch circuit having protection function comprising:

• an electric power element for receiving a control signal via a switch and supplying power from a power source to a load according to said control signal;
• temperature detecting means for detecting the temperature in the neighborhood of said electric power element;
• and
• control means for opening said switch so as to interrupt input of said control signal to said electric power element when said temperature detected by said temperature detecting means exceeds a predetermined temperature;
• wherein
• said control signal includes periodic starting points for turning on and off, and
• said switch circuit further comprises interruption status retaining means for retaining an interruption status of said switch, in which input of said control signal to said electric power element is interrupted, and for releasing said interruption status after said temperature detected by said temperature detecting means no longer exceeds said predetermined temperature, at a next occurring starting point of said signal.