Varistors or voltage-dependent resistors play a critical role in electronic circuits, safeguarding them against transient voltage spikes. These spikes can originate from various sources, such as lightning strikes, inductive load switching, or electrostatic discharge. Understanding how to check a varistor is crucial for ensuring optimal circuit performance and preventing damage to sensitive electronic components.
Checking a varistor involves verifying its functionality and identifying potential issues. One common method is using a multimeter to measure the varistor’s resistance in both forward and reverse bias conditions. A properly functioning varistor should exhibit high resistance in reverse bias and low resistance in forward bias. Any significant deviation from these expected values may indicate a faulty varistor.
