Patent ID: 7282682

Claim:
A high frequency heating apparatus for driving a magnetron, comprising: a DC power supply; a series circuit constituted by two pieces of semiconductor switching elements; a resonant circuit in which a primary winding of a leakage transformer and a capacitor are connected, said series circuit being connected parallel to said DC power supply, and one end of said resonant circuit being connected to a center point of said series circuit and the other end of said resonant circuit being connected to one end of said DC power supply in an AC equivalent circuit; driving means for driving said semiconductor switching elements respectively; rectifying means connected to a secondary winding of said leakage transformer; the magnetron connected to said rectifying means; and a variable dead time forming circuit for varying a dead time during which said respective semiconductor switching elements are simultaneously turned OFF in response to a switching frequency, wherein a limitation is provided under which said dead time is not further widened when the switching frequency is increased.