Superfast Energy Discharge

Proven to discharge energy faster than linear resistors.

Metrosil varistors clamp voltage to a required magnitude and absorb energy up to 3x faster than linear resistors.

Non-Linear Vs. Linear Resistors

A simple inductive coil in an electrical circuit can illustrate the superior performance of Metrosil non-linear resistors. If the current in a coil is suddenly switched off, the resulting voltage that impresses on the turns can reach extremely high levels. A resistor can prevent this by passing a current equal to what it was prior to the overvoltage. Shunting a resistor across the coil allows the surge in energy to ‘leak away’. However, unlike a resistor, a Metrosil silicon carbide varistor conducts faster – limiting voltage to a safe level without excessive heat dissipation/power loss under normal conditions.

Circuit Drawing Illustrating how a Varistor Handles Overvoltage Effects after Switching Event
Graph Illustrating That Metrosil Varistors Discharge Energy Faster than Linear Resistors

Varistors discharge energy fast

The resistance of a non-linear resistor varies, which is why the term ‘varistor’ is often used to describe this component. A varistor is passive at low currents but conducts at high currents. When a high current passes through an electrical system the varistor limits the overvoltage. As the energy dies away, the voltage and current reduce. It can be seen that the voltage curve for a varistor is very different to that of a linear resistor. The discharge time for a varistor is much shorter – usually ~30% of the linear discharge time.

Benefits of Metrosil Varistors

  • Homogeneous structure
  • Superfast energy discharge
  • High energy storage capacity
  • Constant electrical properties within each individual disc
  • Robust mechanical design
  • Safe contact-making
  • Simple installation
Side View of a Metrosil 9000 Varistor Assembly with Square Tiles

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