Surge Absorbers

  • Semitec offers both current (Power Thermistor) and voltage surge absorbers (Metal Oxide Varistors). The Power Thermistor is an NTC thermistor device used for suppressing inrush current to an electrical circuit. Applications include; power supplies, lighting, heaters and fan motor speed control. MOV are transient/surge absorbers featuring large surge current handling capability and energy handling capability for absorbing transient overvoltage. The D series achieves this in a compact size. Semitec MOVs feature a wide product range for transient/surge protection from AC 100V- AC 480 V with peak current ratings from 600amps to 7000amps.


  • VRD

    Semitec VRD is a transient voltage suppressor device that is designed to react to sudden or momentary overvoltage conditions. One such common device used for this purpose is known as the transient voltage suppression diode that is simply a Zener diode designed to protect electronic devices against overvoltage. The characteristic of a VRD requires that it respond to overvoltage faster than other common overvoltage protection components such as varistors or gas discharge tubes. This makes the VRD useful for protection against very fast and often damaging voltage spikes. These fast overvoltage spikes are present on all distribution networks and can be caused by either internal or external events, such as lightning or motor arcing.

  • Zenamic

    Semitec Zenamic Metal Oxide Varistor (MOV) is a transient voltage surge absorber. The construction consists of Zinc Oxide ceramic in a matrix of other metal oxides. During normal operation, the MOV is basically used as a shunt mode device where the voltage across it remains well below its clamping voltage. MOVs have much larger current and voltage handling capabilities compared to Zener diodes. Semitec Zenamic Series D offers large transient overvoltage surge absorption capability in a compact size.