c Varistors Circuit
3 Varistors Circuit When wired parallel to a coil, Varistors, voltage-dependent resistors, limit the maximum over voltage, since they become conductive when a specific threshold voltage is exceeded Fig. Basic circuit diagram: varistor Fig. Switching over voltage of a contactor with varistor Advantages : The increase in drop-out time is minimum and clamps the voltage to acceptable levels. Disadvantages : Cost is very high Overview of different protetion circuit .....