Voltage Dependent Resistors (VDR)

Electrical systems and particularly electrical switchgear are seriously endangered by overvoltage pulses. This overvoltage may destroy or impair the function of parts of the system and construction components. This could cause a breakdown of the electrical system or, in cases of electronic circuits, a false instruction cycle with grave consequences. Silicon carbide varistors offer reliable and economical protection against internal overvoltage (i.e. arising within the system or appliance itself) and external overvoltage (i.e. entering the system or appliance from outside). The properties of Silicon carbide varistors, including high energy absorption, short reaction time, a symmetric characteristic curve and high power dissipation makes them suitable for use in a wide variety of applications.

Silicon carbide varistors are used as protection against: Overvoltage in the mains, caused by lightning, inductive or capacitive coupling; Consumption in switch contacts with inductive load; Excessive switch-off voltages in transformers, motor and generator windings and magnet coils. We supply a range of Silicone Carbide Varistors for high performance that are used mainly in electromechanical engineering as protection against over-voltages in field windings of DC machines, chokes and hoisting magnets. The VDRs configuration are adapted to suit each particular case.