A Metal Oxide Varistor (MOV) is a key component in surge protection. It’s designed to guard sensitive electronic circuits against sudden voltage spikes—like those caused by lightning strikes or power line surges.
An MOV is made from a blend of zinc oxide particles sandwiched between two metal plates. Under normal conditions, it acts as an insulator, allowing almost no current to pass. But when the voltage rises above a certain threshold, the MOV’s resistance suddenly drops—essentially turning it into a conductor. This allows excess energy to be diverted safely to ground, protecting the rest of the circuit.
After the spike, the voltage returns to normal, and the MOV’s resistance rises again, resuming its protective standby role. However, each surge stresses the MOV slightly, and repeated hits can degrade it over time—so regular inspection or replacement in surge protectors is good practice.
In short, a MOV is like an electronic safety valve, absorbing potentially destructive surges before they reach delicate components.
