Power control circuit and method of electromagnetic heating device

Abstract

The invention provides a power control circuit of an electromagnetic heating device. The power control circuit comprises a rectifier module, a control module, a power tube and a resonance module. Therectifier module comprises a rectifier bridge. The rectifier bridge has a first port and a second port. The power control circuit further includes a switch connected to the rectifier bridge. The switch switches between the first port and the second port under the control of the control module so that the rectifier bridge outputs a full-wave rectification waveform or a half-wave rectification waveform. The control module drives the power tube to control the resonance module to operate under the full-wave rectification waveform or the half-wave rectification waveform so as to output different heating powers. By means of the switch, the waveform output by the rectifier bridge can be a full-wave rectification waveform or a half-wave rectification waveform, thereby realizing switching between high-power heating and low-power heating. The power control circuit is realized by a hardware circuit, and is simple, reliable, and stable. The invention also provides a power control method of the electromagnetic heating device.

Description

technical field [0001] The invention relates to the technical field of kitchen appliances, in particular to a power control circuit and a power control method of an electromagnetic heating device. Background technique [0002] The heating principle of the electromagnetic heating device is that the electromagnetic heating device generates an alternating magnetic field, and the ferromagnetic material placed in the alternating magnetic field generates heat by itself due to induction. Electromagnetic heating is more common in cooking utensils, such as induction cooker, IH rice cooker, etc. Cooking utensils using electromagnetic heating are popular among users because of their high thermal efficiency, cleanliness, and convenience. Electromagnetic heating cooking utensils need to use IGBT alternating on and off to achieve electromagnetic resonance. When heating with high power, the IGBT works well, but when heating with low power, the loss of IGBT increases, the temperature rises,...

AI Technical Summary

Problems solved by technology

Electromagnetic heating cooking utensils need to use IGBT alternating on and off to achieve electromagnetic resonance. When heating with high power, the IGBT works well, but when heating with low power, the loss of IGBT increases, the temperature rises, and the service life decreases, making the cooking utensils job instability

For this reason, in order to achieve low-power electromagnetic heating, the industry usually adopts the following methods: 1. Realize by intermittent heating, that is, heating for a period of time and stopping heating for a period of time, so as to reduce the heat loss generated by the IGBT during low-power heating, but this The discontinuous heating of the first heating method makes the user experience poor; 2. Using the silicon controlled rectifier wave dropping method, by controlling the switching on and off of the silicon controlled rectifier, half a cycle of the original continuous cycle waveform is lost, but this method needs to be set The zero-crossing detection circuit performs zero-crossing detection, and the thyristor must be controlled to perform on-off actions in each waveform cycle, the circuit cost is high and the stability is not good

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