| 摘要 |
PROBLEM TO BE SOLVED: To prevent the interference noise generation in a multi-port type range by controlling the heating output by keeping the oscillation frequency of an inverter circuit constant. SOLUTION: An inverter circuit 10 of this induction heating cooking device comprises a diode 17 and a transistor 16 connected in series and a capacitor 15 for resonance connected in parallel to the diode and the transistor 16. A control part 20 turns off a transistor 13 after a prescribed time during which the transistor 13 and the transistor 16 are turned on to generate resonance between a heating coil 12 and the capacitor 15. When the collector voltage Vc increases and exceeds an electric power source voltage Vb, the direction of the electric current flowing in the capacitor 15 is turned to the transistor 16 side and the resonance is temporarily stopped. Consequently, the electric current flowing in the heating coil 12 is limited. Due to that, the on time of the transistor 16 is fixed and on the other hand, the heating output is lessened more as the on time of the transistor 13 is shortened more. As a result, without fluctuating the operational frequency of the inverter circuit 10, the heating electric power can be adjusted. |
