Patent ID: 9391445
Filing Date: 2016-07-12
CPC Classification: H01F,H02G,H02H,H05B

Claim Text:
1. A surge protection circuit, applied to a switching power supply, wherein an output end of the power supply is connected to a terminal device, and the power supply comprises a transformer, a ground wire end at a high voltage side of the transformer is grounded, and a ground wire end at a low voltage side of the transformer is not grounded, the surge protection circuit comprising: a surge protection tube, wherein one end of the surge protection tube is electrically connected to the ground wire end at the high voltage side of the transformer, the other end of the surge protection tube is electrically connected to the ground wire end at the low voltage side of the transformer, and the ground wire end at the low voltage side of the transformer is electrically connected to a ground wire end of the terminal device, and wherein the ground wire end at the high voltage side of the transformer, the surge protection tube, and the ground wire end at the low voltage side of the transformer form a loop such that when a surge voltage on the terminal device is greater than a discharge voltage of the surge protection tube, the surge protection tube is conducted, and the surge protection tube discharges the surge voltage on the terminal device to the ground wire end at the high voltage side of the transformer.