Varistors (Metal Oxide Varistors, MOV) is a significant non-ohmic conductive electronic components. The resistance will change with the external voltage and current. Therefore, the voltage characteristic (V-I) curve has a significant non-linear feature. Varistors are used in electronic circuits for protection because the transient voltage surge of power supply system may damage the circuit. When high voltage occurs, the resistance of varistor gets down and make the current shunt, and thus to protect sensitive electronic equipment to avoid transient voltage damage or interference.
The working theory of varistors : when the varistors in standby mode, the varistors have a high impedance (several megohms) as opposed to the protected electronic components and will not affect the characteristics of the original design of the circuit. But when an instant surge occurs (exceeds the breakdown voltage of varistors), the surge impedance of the varistors becomes low (only a few ohms) and causes a short circuit, so that electronic products or some more precise devices are protected.
- Power supply surge protection
- Communications devices
- Microprocessors, integrated circuits, transistors and other semiconductor components to protect
- Motor control system
- Industrial equipment
- Smoke detectors
High Surge Series