| 摘要 |
Embodiments of the present invention provide a surge protection circuit, a switching power supply, and a surge protection method, which can prevent a power supply from being damaged by a high energy surge voltage discharged from a terminal device to an output end of a power supply. The surge protection circuit is applied to the switching power supply, where an output end of the power supply is connected to the terminal device. The power supply includes a transformer, where 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 circuit includes a surge protection tube, where one end of the surge protection tube is electrically connected to the ground wire end at the high voltage side of the transformer, and the other end of the surge protection tube is electrically connected to the ground wire end at the low voltage side of the transformer. The ground wire end at the low voltage side of the transformer is electrically connected to a ground wire end of the terminal device. The ground wire end at a 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. 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 discharges the surge voltage on the terminal device to the ground wire end at the high voltage side of the transformer. The embodiments of the present invention are applicable to the field of electronic technologies. |
