Induction heating equipment

Abstract

An induction heating device that can heat aluminum pans and the like while suppressing pan vibration noise. During the on-time of the second switching means 57, energy is accumulated at the choke coil 54, while a resonant current having a period shorter than the on-time of the second switching means 57 or the excitation time of the first switching means 55 flows in the heating coil 59. generated at , so that the energy accumulated at the choke coil 54 is transferred to the second smoothing capacitor 62 during the off period of the second switching device 57 , that is, during the on period of the first switching device 55 . The output power is then supplied from the smoothing capacitor 62 to the heating coil 59, thereby reducing pan vibration noise caused by the pulsating current of the input voltage.

Description

technical field [0001] The invention relates to induction heating devices, such as induction heating cooking units, in which highly conductive and low permeability loads, such as aluminum pans, can be efficiently heated; the invention also relates to induction heating type water heaters, humidifiers, irons, etc. Wait. Background technique [0002] In the case of conventional induction heating equipment such as induction heating cooking equipment, for example, Japanese Patent Application No. 1989-246783 discloses a technology capable of preventing pan vibration noise and power factor reduction when heating an aluminum pan, and for example, Japanese Patent Application No. 2001-160484 discloses techniques for reducing conversion loss and for heating an aluminum pan using high frequency waves. [0003] Figure 9 is the circuit included in the above-mentioned Japanese Patent Application No. 1989-246783. exist Figure 9 Among them, a bridge circuit 2 for rectifying 100v AC (alte...

AI Technical Summary

Problems solved by technology

[0006] However, the above-mentioned prior art has many problems: that is, in order to effectively heat aluminum pans and iron pans, a costly and complicated circuit structure capable of changing the number of turns of the heating coil 18 is required; The excitation frequency of the conversion device 15, 17 is set to the same 50kHz, thus causing a huge conversion loss in the conversion device 15, 17; and if the resonance point tracking method is used to reduce the conversion loss, an additional circuit such as a control circuit is required and changing the supply voltage of the circuit for output power improvement

However, even combining this method with the method disclosed in Japanese Patent Application No. 2001-160484 cannot achieve proper output control because the resonance current weakens and cannot maintain

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