Magnetron filament control circuit, magnetron power supply circuit

Abstract

Provided are a magnetron filament control circuit and a magnetron power supply circuit, belonging to the field of household electrical appliances. A magnetron (10) filament control circuit (31) comprises: a switch tube (27), connected in series between a flyback diode (25) and a direct-current input terminal; an inductor (24), connected in series to a filament (11) of the magnetron (10) between the two ends of the flyback diode (25); the flyback diode (25) cuts off when the switch tube (27) closes; a temperature sensor (29), configured to detect the temperature of the magnetron (10); a switch control circuit (28), configured to control, according to the temperature of the magnetron (10), the switch tube (27) to close or disconnect, such that if the temperature of the magnetron (10) is within a predetermined threshold range, then the direct current alternating in magnitude and height flows through the filament (11) of the magnetron (10). The temperature sensor (29) and switch control circuit (28) work together so that the current entering the magnetron filament (11) is controlled according to the temperature of the magnetron (10), ensuring that the filament (11) stabilizes transition of electrons.

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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