Electric cooker and zero-crossing calibration circuit and zero-crossing calibration method thereof

Abstract

The invention discloses an electric cooker and a zero-crossing calibration circuit and a zero-crossing calibration method thereof. The electric cooker comprises a resonance circuit, a power switch tube and a drive module. The resonance circuit is connected with a collector electrode of the power switch tube, and has a first node. The zero-crossing calibration circuit comprises a zero-crossing detection unit, a resonance voltage detection unit and a control unit, wherein the zero-crossing detection unit is used for detecting a zero-crossing point of an input AC power supply to output a zero-crossing signal; the resonance voltage detection unit is connected with the first node to detect resonance voltage of the first node; the zero-crossing detection end of the control unit is connected withthe zero-crossing detection unit; the AD sampling end of the control unit is connected with the resonance voltage detection unit; and the control unit judges that zero-cross detection is wrong, and carries out processing on the zero-crossing signal in the process where the zero-crossing detection end detects that the zero-passing signal changes from a falling edge to a rising edge, and when the AD sampling end samples the resonance voltage of the first node and the resonance voltage of the first node is larger than a preset voltage.

Description

technical field

[0001] The invention relates to the technical field of cooking appliances, in particular to a zero-crossing calibration circuit of an electric cooker, an electric cooker and a zero-crossing calibration method of the electric cooker. Background technique

[0002] Electromagnetic induction heating electric cooker has been widely used. For the electromagnetic induction heating control circuit in this type of electric cooker, there is a continuous low-power control method that takes half-wave alternating current as the heating cycle and adopts the method of dropping waves during heating, because the resonance of electromagnetic induction heating needs half-wave alternating current For the frequent start and stop of the cycle, it is necessary to correctly detect and judge the zero-crossing point of the AC power supply. When the zero-crossing point is misjudged, the current noise of the heating and starting of the electric cooker will increase, and the reliability...

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