Working principle of surge protector

Surge protection device (Surge protection Device) is an indispensable device in the lightning protection of electronic equipment. It used to be called "lightning arrester" or "overvoltage protector" in English abbreviated as SPD. 

The instantaneous overvoltage into the power line and signal transmission line is limited to the voltage range that the equipment or system can withstand, or the powerful lightning current is discharged into the ground to protect the protected equipment or system from impact and damage.

The type and structure of a surge protector are different for different purposes, but it should at least contain a non-linear voltage limiting element. The basic components used in surge protectors are: discharge gap, gas-filled discharge tube, varistor, suppression diode, choke coil, etc.