Input power supply selection circuit

Abstract

The invention provides an input power supply selection circuit. The circuit comprises a load, at least one input power supply which can provide a work power supply for the load, and an input selectioncircuit suitable for selecting one input power supply as the work power supply of the load among at least one input power supply, wherein the work power supply is a direct current power supply or analternating current power supply. The circuit further comprises a detection control unit which controls the input selection circuit to switch the work power supply of the load according to the voltageof at least one input power supply, the output end voltage of the input selection circuit, and the voltage of the load, and a load switch branch. One end the load switch branch is connected with theload, and the other end is connected with the output end of the input selection circuit. The load switch branch is suitable for controlling the closing and opening of the circuit where the load is located. The detection control unit is further suitable for controlling the closing and opening of the load switch branch. According to the invention, the design of the contact protection of the input selection switch is simplified, and the switching capacity requirement of the load switch branch is reduced.

Description

technical field [0001] The invention relates to the technical field of power supplies, in particular to an input power selection circuit. Background technique [0002] Some power supply systems usually set up multiple power supplies to achieve input redundancy. The matching input power selection circuit usually consists of multiple relay switches, and selects one of the multiple input power supplies for power supply. When the selected When the input power cannot work normally, the input power selection circuit will switch the power to another input power that can work normally to ensure that the power supply system can work normally. [0003] If the circuit includes a capacitive load and the phases of the power supply voltage before and after switching are different, during the power switching process, if the switch is operated with power on, an arc will usually be generated, which will cause the switch to overheat and the contacts to stick, resulting in switch failure. The...

AI Technical Summary

Problems solved by technology

[0003] If the circuit includes a capacitive load and the phases of the power supply voltage before and after switching are different, during the power switching process, if the switch is operated with power on, an arc will usually be generated, which will cause the switch to overheat and the contacts to stick, resulting in switch failure

Therefore, a relay switch with switching capacity needs to be provided in the input power selection circuit, which increases the size and cost of the input selection circuit, and increases the design complexity of related circuits

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