Understanding the Surge Absorber

Understanding the Surge Absorber

 Surge absorbers are designed to absorb and dissipate the energy of the surge within the device itself, thereby protecting the equipment downstream.

Construction:

  • Surge absorbers typically use materials with nonlinear resistance characteristics, such as metal oxide varistors (MOVs). These materials have a high resistance at normal operating voltages but become highly conductive at higher voltages, allowing them to absorb the surge energy.
  • Surge absorbers include capacitors and inductors to filter and smooth out transient voltages. These components help in mitigating the effects of fast-rising voltage spikes and maintaining the stability of the power supply.

Working Principle

Under normal voltage conditions, the surge absorber presents a high resistance, allowing the standard operating voltage to pass through without significant attenuation or energy loss. When a transient over-voltage occurs, the nonlinear resistance material’s conductivity increases sharply, allowing it to absorb and dissipate the excess energy as heat. The capacitors and inductors, if present, help filter out high-frequency components of the surge, further protecting the connected equipment.

After the surge has been absorbed, the device returns to its high-resistance state, ready to protect against future surges.