PURPOSE: By not using the separate temperature sensing line and one heat ray of heater, the drive control circuit of the electric mat senses the driving state of heater. CONSTITUTION: The power supply unit(1) changes the inputted orthovoltage into the direct current voltage. The central processing unit(2) controls the system part in relation with the heater operation. Supplies the driving voltage to the relay driving part(3) and relay switch is heater. The heater operation controller(5) controls the conduction angle of the thyristor(6).
