Magnetron filament control circuit and magnetron power supply circuit

Abstract

The invention provides a magnetron filament control circuit, a magnetron power supply circuit and a microwave heating device, and belongs to the field of design of a household appliance. The magnetronfilament control circuit comprises a switch tube, an inductor, a freewheeling diode, a temperature sensor and a switch control circuit, wherein the switch tube and the freewheeling diode are connected in series between DC input ends, the inductor and a magnetron filament are connected in series between two ends of the freewheeling diode, the freewheeling diode is cut off when the switch tube is switched on, the temperature sensor is configured to detect a temperature of a magnetron, the switch control circuit is configured to control the switch tube to be switched on or switched off accordingto the temperature of the magnetron, so that a direct current of which a high current and a low current change alternatively passes through the magnetron filament when the temperature of the magnetron is within a preset threshold range. By matching of the temperature sensor and the switch control circuit, a current input to the magnetron filament is controlled according to the magnetron temperature, and the filament can be enabled to stabilize electron transition.

Description

technical field [0001] The invention relates to the design field of household appliances, in particular to a magnetron filament control circuit, a magnetron power supply circuit and a microwave heating device. Background technique [0002] A magnetron is an electric vacuum device used to generate microwave energy. Essentially a diode placed in a constant magnetic field. Under the control of the perpendicular constant magnetic field and constant electric field, the electrons in the tube interact with the high-frequency electromagnetic field to convert the energy obtained from the constant electric field into microwave energy. [0003] The electrons in the magnetron are generated by the filament (or cathode). There are two main power supply methods for the magnetron filament of the existing frequency conversion microwave oven: one method is to provide a basically stable AC voltage, and the continuous maximum power supply during the whole working process , so as to maintain t...

AI Technical Summary

Problems solved by technology

This kind of filament power supply method is relatively simple and direct, but it is a continuous maximum power supply during the whole working process, which keeps the filament at a high temperature state, which will inevitably reduce the service life of the magnetron filament, and at the same time, the magnetron filament keeps working at maximum power. It is also a waste of energy, which reduces the efficiency of the microwave oven

In the prior art, on the basis of the first method, a switch device is connected in series in the filament current rectification circuit to provide an adjustable power supply voltage under different working states of the microwave oven through the on-off method, although it solves the problem of the first method. A way of energy waste and improved service life, but because this solution works in on-off mode, when it is disconnected, the magnetron may have the possibility that electrons cannot transition, and the work stability is not strong

[0005] For the above problems, there is no good solution in the prior art

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