Patent ID: 7312427

Claim:
A high-frequency dielectric heating device for heat-treating a material to be heated, comprising: a microwave output unit including: an inverter unit for inverting a direct current into an alternating current of a predetermined frequency by switching a semiconductor switching element by using an inverter control circuit, heat-radiating fins on which the semiconductor switching element is mounted to radiate the heat generated by the semiconductor switching element, a printed board having a thermistor for dectecting the temperature of the semiconductor switching element, the thermistor being soldered to a leg portion of the semiconductor switching element or near to the leg portion thereof on the side of the soldering surface of the printed board, a booster transformer for boosting the output voltage of the inverter unit, a high-voltage rectifier unit for doubling and rectifying the output voltage of the booster transformer, and a magnetron for radiating the output of the high-voltage rectifier unit as microwave; and wherein the inverter unit has a power-down control function for permitting the output power of the inverter unit to vary depending upon the resistance of the thermistor after the start of the magnetron.