How to pick a good varistor?

In practice, it should be the right choice resistor. This article describes the common resistor fixed resistors, fuse resistors, thermistors, Metal oxide varistors, varistor, humidity resistance and other selection methods. ʱ??
Varistor selection
Varistors are mainly used in a variety of electronic products, over-voltage protection circuit, it has a variety of models and specifications. The main parameters of the selected varistor (including nominal voltage, maximum continuous operating voltage, maximum limit voltage, current capacity, etc.) must comply with the requirements of the application, in particular, the nominal voltage must be accurate. The nominal voltage is too high, would not achieve the over-voltage TGE metal oxide varistor basics protection, nominal voltage is too low, the varistor easily malfunction or breakdown.