Views:5 Author:Site Editor Publish Time: 2018-03-28 Origin:Site
1. distinguish power protection, or signal lines, data line protection varistors, they should meet the requirements of different technical standards.
2. according to the difference of the continuous working voltage applied on the varistor, the varistor used in the cross-power line can be divided into two types: AC or DC. The characteristics of the varistor under these two kinds of voltage stress are different. 3. according to the abnormal overvoltage characteristics of varistor, the varistor can be divided into three types: surge suppression type, high power type and high energy type. Surge suppression: a varistor used to suppress transient overvoltages such as lightning overvoltages and operating overvoltages, which are random, aperiodic, and the peak value of current voltages may be high. Most varistors fall into this category. High power type: a varistor that is used to absorb a continuous group of pulses occurring in a period, such as a varistor connected to a switching power converter, where the impulse voltage period occurs and the period indicates that the energy value can generally be calculated. The peak value of voltage is not large, but because of the high frequency, its average power is quite large. High energy type: a varistor used to absorb magnetic energy in large inductance coils such as generator excitation coils, lifting electromagnet coils and so on. For such applications, the main technical index is energy absorption capacity. The protection function of varistor, in most applications, can be acted repeatedly many times.