Electromagnetic heating circuit utilizing single-chip microcomputer to automatically track resonant frequency

Abstract

The invention discloses an electromagnetic heating circuit utilizing a single-chip microcomputer to automatically track a resonant frequency. The electromagnetic heating circuit comprises a filtering capacitor C1, a resonance capacitor C3, a magnet exciting coil L1 and a single-chip microcomputer control circuit U2; a push-pull type power switch circuit is connected between the filtering capacitor C1 and the resonance capacitor C3; a current sampling conversion circuit is connected between the magnet exciting coil L1 and the single-chip microcomputer control circuit U2; a push circuit U1 is connected between the single-chip microcomputer control circuit U2 and the push-pull type power switch circuit; the push-pull type power switch circuit comprises an IGBT (insulated gate bipolar translator) Q1 I and an IGBT Q2 II, which internally respectively comprise a booster diode with a collector C, an emitter E and a grid G; the single-chip microcomputer control circuit U2 is internally provided with a voltage comparator; and the current sampling conversion circuit comprises a transformer Tr and two diodes D2 and D3 in reverse parallel connection with the secondary side of the transformer Tr. The electromagnetic heating circuit utilizing the single-chip microcomputer to automatically track the resonant frequency has higher anti-jamming capacity, is capable of improving the work stability of the circuit and can be applied to the electromagnetic heating in industrial production.

Description

technical field

[0001] The invention relates to an electromagnetic heating device, in particular to an electromagnetic heating circuit which uses a single-chip microcomputer to automatically track a resonant frequency, and belongs to the field of electromagnetic heating. Background technique

[0002] In order to improve the electrothermal conversion efficiency, electromagnetic heating is widely used in industrial production. In the process of electromagnetic heating, the structure or temperature of the heating object is always changing constantly, so that the inductance of the electromagnetic coil is constantly changing, and the resonant frequency of the electromagnetic output circuit is constantly changing. The existing electromagnetic heating circuit mostly uses a single power tube (IGBT) to drive the excitation coil. As shown in Figure 3, the circuit cannot automatically track the resonant frequency or has a small resonant frequency tracking range, poor anti-interference ...

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