Electromagnetic heating device and power control method

Abstract

The invention provides an electromagnetic heating device and a power control method; the electromagnetic heating device comprises an AC power supply circuit (10), a rectification circuit (20), a filter circuit (30), a heating loop (40), a controller (50), an electronic switch (60), and a zero cross detection circuit (70); the filter circuit (30) comprises a filter capacitor (31); the filter capacitor (31) is connected in series with the electronic switch (60) and connected in parallel between the rectification circuit (20) and the heating loop (40); the input end of the zero cross detection circuit (70) is connected between the AC power supply circuit (10) and the heating loop (40); the controller is respectively electrically connected with the heating loop (40), a control end of the electronic switch (60) and an output end of the zero cross detection circuit (70). The method can reduce the heating of the IGBT in a low power heating process, thus improving the power range of low powerheating.

Description

technical field [0001] The invention relates to the technical field of household appliances, in particular to an electromagnetic heating device and a power control method. Background technique [0002] The electromagnetic heating device uses the magnetic field line generated by the coil plate to cut the pot to generate eddy current, and the Joule heating effect of the eddy current makes the pot heat up, thereby realizing heating. Electromagnetic heating device has become a kind of cooking utensil with high frequency of use in people's life due to the advantages of convenient and quick heating and no open flame. [0003] Electromagnetic heating devices usually have multiple power levels. When realizing low-power heating, there are many circuit implementation methods. At present, the more common implementation methods include switching resonant capacitors and using relay + diode chopping. Among them, the way to switch the resonant capacitor is to use a large-capacity resonant...

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Problems solved by technology

[0004] However, the above method of switching the resonant capacitor, when heating with low power, the resonant frequency is very high, and the loss of the insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) is very large, resulting in a large amount of heat generated by the IGBT. In order to ensure the safety of the circuit Work, the power cannot be too small; the above-mentioned method of relay + diode chopping is also due to the large heat generated by the IGBT during low power heating, resulting in the power cannot be too small

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