Is there a difference between the surge protector and the varistor in the circuit board?

Varistors are common resistors in our life. Do you have a difference between a surge protector and a varistor in a circuit board? Do you know the working principle of the surge protector varistor? Let's take a look at it with Xiaobian!

Surge protector varistor working principle:

A varistor is a sensitive component that is non-linear in volt-ampere characteristics and is typically connected in parallel to the input of the protected device. Under normal voltage conditions, the varistor has a high impedance and a small leakage current, which can be regarded as an open circuit and has little effect on the circuit. The varistor will drop sharply and quickly turn on when the circuit has an overvoltage. Its current can be increased by several orders of magnitude. At the same time, the overvoltage is clamped to a certain value, which can protect other devices in the circuit from overvoltage. And damaged.

The varistor used in the surge protector works the same as the varistor used in the circuit board. If there is any difference, the difference is only reflected in the difference of the parameters, because the protection range is different, the voltage Levels, surge current passing ability or different, of course, this difference will also be reflected in the external dimensions.