JPS6412493A - High-frequency heating device - Google Patents

Abstract

PURPOSE:To shorten a heating time and to remove excessive quality in constitutional parts by equipping a power converter, which has one semiconductor element and is formed in prescribed composition, a semiconductor element controlling part, an electric wave radiation part, a start-up controlling part in which an electromotive wave output is enlarged at the beginning of operation. CONSTITUTION:A transistor 28 is switched by a signal of a controlling part 34, so that power at a commercial power source is converted into that at audible frequency or above, and its voltage is supplied to a primary coil 35 of a boosting transformer 27 and raised and rectified so as to oscillate a magnetron 32. A signal is sent to the start-up part 34 from a current detector 36. In the start-up part 34, an on time of the transistor 28 is controlled by the use of an error between this signal and a reference signal, so that an input current is kept to be a prescribed value and that an output of the magnetron 32 is controlled. When a heating start command 40 is given to a start-up controlling part 41, electromagnetic wave energy is generated with larger output for a prescribed time at the beginning of the operation in the part 41 than at a stationary time, so that a heating time can be shortened. Cooling function of constitutional parts and quality in heat-resisting specifications can be made appropriate by this composition so that excessive quality can be removed.