Power supply circuit and power supply device

Abstract

Embodiments of the invention provide a power supply circuit and a power supply device, and relate to the field of circuits. The power supply circuit and the power supply device are used for guaranteeing normal work of power devices when the external mains supply is in a state of under-voltage. The circuit comprises an external mains supply, a power device, a conversion circuit and a single-phase inverter circuit. The input end of the conversion circuit is connected with the external mains supply, and the output end of the conversion circuit is connected with the input end of the single-phase inverter circuit. The output end of the single-phase inverter circuit is connected with the power device. The conversion circuit is used for converting the output voltage of the external mains supply into a first direct voltage. The single-phase inverter circuit is used for inverting the first direct voltage into the rated voltage of the power device, converting the rated frequency of the external mains supply into the rated frequency of the power device and inputting the rated frequency and the rated power of the power device into the power device.

Description

technical field [0001] The invention relates to the field of circuits, in particular to a power supply circuit and a device. Background technique [0002] With the development of science and technology, air conditioners have entered thousands of households. Generally, the air conditioner is divided into indoor unit and outdoor unit. The outdoor unit is equipped with a four-way valve and a fan motor. The four-way valve is a control device for switching the cooling mode and heating mode of the air conditioner; the fan motor is used to drive the fan The condenser and some power devices dissipate heat, and if the four-way valve and the fan motor need to work, the four-way valve and the fan motor need to be powered. [0003] In the prior art, the external mains is usually connected to the four-way valve and the fan motor respectively through a controllable switch (for example, a relay, etc.), because the rated voltages of the four-way valve and the fan motor are the same as the ...

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Problems solved by technology

[0004] However, in the above implementation process, when external factors (such as grid aging, overload, etc.) cause the external mains to be in an undervoltage state, the voltage provided to the four-way valve and fan motor is lower than the rated voltage of the four-way valve and fan motor. Voltage, so that the magnetic force generated by the four-way valve is insufficient, causing the switching action to fail; the speed of the fan motor is reduced, that is to say, when the external mains is under voltage, the four-way valve and the fan motor will not work normally.

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