OVER-VOLTAGE PROTECTION CIRCUIT FOR SWITCHING POWER SUPPLY, SWITCHING POWER SUPPLY, AND COMPRESSOR

摘要

Provided are an over-voltage protection circuit for a switching power supply, the switching power supply, and a compressor. The over-voltage protection circuit comprises: a first voltage sampling module, with one end of the first voltage sampling module being connected to a bus of a switching power supply and the other end thereof being grounded; a switch module connected to the first voltage sampling module; a second voltage sampling module, with one end of the second voltage sampling module being connected to an auxiliary winding of the switching power supply and the other end thereof being grounded; and a comparison circuit, with an input end of the comparison circuit being connected to the second voltage sampling module and being connected to the first voltage sampling module by means of the switch module, and an output end of the comparison circuit being connected to a control apparatus of the switching power supply. According to the present application, where the protection pins of a switching power supply are limited, only one protection pin is used, double-voltage sampling is used, input and output double-over-voltage protection is realized, and thus the impact of grid voltage fluctuation and a power-on impulse voltage on the switching power supply is effectively reduced.