The main components of the anti-surge circuit are discharge tubes, varistors, voltage clamping transient mimetic diodes (TVS), voltage switching transient mimetic diodes (TSS), thermistors (PTC) and so on. In the protection device, the gas discharge tube is characterized by a large amount of flux, but the response is slow, high breakdown voltage; TVS tube flux is small, fast response, good voltage clamping characteristics; varistor is between the two.
TVS diode components, including high-power products are mainly used in the power feeder, low-power products are mainly used in high-density installation occasions. For high-density installations, TVS arrays and surface mount packages are also available.
The main reason why varistors are widely used in the industry is that they have the advantages of high impulse current resistance, fast response time and low cost. However, as we all know, there is a bottleneck in MOV technology that cannot be broken through so far, and MOVs have a good insulation impedance, i.e., low leakage current, before they are impacted; however, when subjected to inductive lightning, the varistors will deteriorate, resulting in a decrease in insulation impedance and an increase in leakage current. impedance decreases and the leakage current increases. Generally used in the power supply and voltage resistance in series to improve the protective effect.