Varistor Selection Principles

If the voltage level of the electrical equipment is low Vo and the surge energy is relatively large, a varistor with a lower varistor voltage V1mA and a larger diameter can be selected; if the Vo is higher, the varistor voltage V1mA can be selected. Higher varistors can protect both electrical equipment and varistor life.

Varistors are mainly used in overvoltage protection circuits of various electronic products. It has a variety of models and specifications. The main parameters of the selected varistors (including nominal voltage, continuous operating voltage, limiting voltage, flow capacity, etc.) must meet the requirements of the application circuit, especially the nominal voltage must be accurate. If the nominal voltage is too high, the varistor will not achieve overvoltage protection. The nominal voltage is too low. The varistor is susceptible to malfunction or breakdown.