Electromagnetic heating device and voltage sampling circuit of electromagnetic heating device

Abstract

The invention discloses a voltage sampling circuit of an electromagnetic heating device. The voltage sampling circuit comprises a switch power source inverting module and a flyback output and feedback module, wherein the switch power source inverting module is used for converting a first direct current power source outputted by a rectifier in the electromagnetic heating device into a high-frequency signal, and comprises a high-frequency transformer and a power source chip, the high-frequency transformer comprises a primary winding, a first secondary winding, a second secondary winding and a third secondary winding, the flyback output and feedback module is used for outputting a second direct current power source through the first secondary winding, and feeding the voltage fluctuation of the second direct current power source back to the power source chip through the second secondary winding, a forward sampling module is connected with the third secondary winding to sample the voltage so as to generate a sampling signal, and a controller is used for sampling the voltage of the first direct current power source according to the sampling signal. The voltage sampling circuit has the characteristics that the voltage isolation sampling is realized by a forward sampling winding and the forward sampling module; the temperature rise is low, the size is small, the structure is simple, the cost is low, and the like. The invention also discloses the electromagnetic heating device.

Description

technical field [0001] The invention relates to the technical field of electromagnetic heating, in particular to a voltage sampling circuit of an electromagnetic heating device and an electromagnetic heating device. Background technique [0002] The voltage sampling circuit is a necessary circuit in an electromagnetic heating device such as an induction cooker. Its function is very important. It can be used to detect the voltage signal, and then calculate the power of the electromagnetic heating device through the detected voltage signal and current signal, and then according to the calculated power. The electromagnetic heating device is intelligently controlled. [0003] Currently commonly used voltage sampling circuits include: 1) resistor divider sampling circuit, which reduces the 220V / 380V AC power to within 5V through a high-power resistor, which is suitable for the input signal of a controller such as MCU (MicroControlUnit, micro control unit); 2) voltage The transfo...

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Problems solved by technology

[0004] Among them, the resistance divider sampling circuit cannot realize isolated sampling, so it cannot meet the requirements of some schemes under isolated conditions, and the low-frequency transformer made of silicon steel sheet is used in the voltage transformer sampling circuit, so there are low precision, large magnetic loss, and temperature rise. High, bulky, inconvenient assembly, and high cost; in the current transformer sampling circuit, because the current transformer signal is relatively small, a dedicated amplification processing circuit is required, so there are many components and the sampling circuit is more complicated. Shortcomings; in addition In the optocoupler sampling circuit, the use of conventional optocouplers that are greatly affected by temperature has the problem of low sampling accuracy, while the use of high-precision optocouplers has the problem of high cost

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