Induction cooker surface temperature control circuit and method

Abstract

According to the induction cooker surface temperature control circuit and method, a first pin of a triode Q1 in a zero-cross detection circuit is connected with a zero-cross signal receiving pin of a main control chip circuit, a second pin of the triode Q1 is connected with one end of a resistor R2, and a third pin of the triode Q1 is connected with the other end of the resistor R2; one end of the resistor R1 is connected between the third pin of the triode Q1 and the resistor R2, and the zero cross detection circuit is connected between the EMC protection circuit and the rectification filter circuit through the other end of the resistor R1; the preset temperature of the surface of the induction cooker by a user is obtained, the preset temperature and the current temperature of the surface of the induction cooker are judged and compared, and heating control is performed on the temperature in the induction cooker by adopting various power combinations, so that more accurate and more stable temperature is achieved. According to the invention, when power of the induction cooker is relatively low, heating can still be carried out without stopping, so that the temperature of food in a pot can be controlled more accurately and more constantly by utilizing different high and low powers.

Description

technical field [0001] The invention relates to the technical field of induction cooker, in particular to a circuit and method for controlling the surface temperature of an induction cooker. Background technique [0002] The induction cooker is based on the phenomenon of electromagnetic induction, using alternating current to pass through the coil to generate an alternating magnetic field with a constantly changing direction. Eddy currents will appear inside the conductor in the alternating magnetic field (the reason can be referred to Faraday's law of electromagnetic induction), which is eddy current The vortex electric field promotes the movement of carriers in the conductor (electrons in the pot are definitely not iron atoms); the Joule heating effect of the eddy current causes the conductor to heat up, thereby realizing heating. [0003] At present, some electric control schemes of induction cookers adopt a single-tube (single IGBT) parallel resonance scheme. Since the I...

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Problems solved by technology

This discontinuous heating method is also called intermittent heating. When this 1000W intermittent heating method needs to control the temperature of food or water in the pot, the temperature of the food in the pot changes greatly, usually above 10 degrees, or even larger, and the error is large. Large, can not meet the temperature more accurate requirements

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