Everyday electronic devices—smartphones, rice cookers, and more—contain components that protect them from voltage surges. One such component is the varistor.
Varistors are designed to absorb excess voltage and protect circuits from damage. Their effectiveness depends on the rated voltage, which is often misunderstood. Many people assume that a higher varistor voltage rating is automatically better—but that’s not always the case.
Why a Higher Rated Voltage Isn’t Always Ideal
A varistor’s rated voltage should match the normal operating voltage of the device. If the rated voltage is too high:
The varistor may not clamp voltage surges effectively, leaving other components at risk.
The device may experience overvoltage damage before the varistor engages.
If the rated voltage is too low:
The varistor may trigger unnecessarily, wasting energy or potentially causing circuit disruptions.
Thus, choosing a varistor with a voltage rating appropriate for the device is key to achieving both effective protection and reliable operation.
Conclusion
Varistor protection isn’t about “the higher the voltage, the better.” It’s about matching the varistor’s rated voltage to the device’s operating conditions. Selecting the correct voltage ensures optimal protection and avoids unnecessary failure of both the varistor and the circuit.
This article is provided by JYH HSU (JEC) Electronics. JEC is a research, development, production, and sales-oriented company specializing in manufacturing and selling various electronic components such as capacitors and resistors.
Post time: Dec-11-2025