Patent ID: 9357591
Filing Date: 2016-05-31
CPC Classification: H05B,Y02B

Claim Text:
1. A high frequency heating apparatus for driving a magnetron, comprising, a direct current power supply; a series circuit comprising a pair of semiconductor switching elements; and a resonance circuit connected with a primary coil of a leakage transformer and a capacitor; in which the series circuit is connected to the direct current power supply in parallel, and, in an AC equivalent circuit, an end of the resonance circuit is connected to an intermediate point of one end of the series circuit and the other end is connected to an end of the direct current power supply, and further comprising, a drive means for driving the respective semiconductor switching elements; a rectifying means, which is connected to a secondary coil of the leakage transformer; and a magnetron, which is connected to the rectifying means, wherein a variable dead time preparation circuit which allows a period for which respective semiconductor switching elements are simultaneously turned off to vary in response to a switching frequency is provided, wherein the variable dead time preparation circuit allows the dead time to increase in response to a rise in the switching frequency when the switching frequency is greater than or equal to a predetermined switching frequency, and wherein the variable dead time preparation circuit allows the dead time to remain constant or to increase minutely as a function of the switching frequency when the switching frequency is less than the predetermined switching frequency.