Views: 3 Author: Site Editor Publish Time: 2018-04-20 Origin: Site
1) Interline application circuit
The characteristic of this circuit is that the varistor R is parallel between the power line and the signal line or between the signal line and the ground line. When the voltage at the two ends of R1 reaches the breakdown voltage, the R1 resistance decreases rapidly, and the purpose of overvoltage protection is achieved. As a varistor, the typical application is to protect the electronic products when the power line and the long distance transmission signal line meet the lightning strike and cause the conductor to have surge pulse and so on. In general, the interline access varistor can be effective for the induction pulse between the lines, while the on-line connection varistor between the ground and the line is effective for the induction pulse between the transmission line and the earth.
2) Inductive load application circuit
In the circuit, assuming that R1 is a varistor, when the shop assistant switch S1 is disconnected, the two ends of the inductive load will produce a very large reverse EMF. R1 is then used to limit this reverse EMF to achieve the purpose of protection. Usually the varistor can be connected directly on the inductive load, but the RC series absorption circuit can be considered according to the type of current and the magnitude of energy.