Miniaturized in size, capable of handling high current, with fast response and stable performance, varistors have earned a significant place in the electronic components market, finding extensive application in electronic circuits and household appliances. How do varistors, used in various electronic products, work? What is their operating principle?
The working principle of varistors:
When the voltage applied to the varistor from external sources is lower than the varistor’s threshold voltage, the current passing through the varistor is very small, and the varistor remains in an open state.
When the voltage applied to the varistor exceeds its threshold, the current through the varistor increases, reducing its resistance. At this point, the varistor is in a closed state, minimizing the impact of voltage on the circuit, thus protecting other electronic components.
You can think of the operating principle of a varistor like a faucet’s switch. Consider the varistor as the “faucet” in the circuit. When the flow is low, the water flow from the faucet is small, equivalent to a low-voltage state in the circuit. However, when the flow increases, the water flow from the faucet also increases, corresponding to a high-voltage state in the circuit.
Therefore, in cases of overvoltage in the circuit, the “faucet” opens rapidly, allowing current to flow and protecting downstream circuits and other electronic components.
This article is provided by JYH HSU Electronics, a manufacturer of electronic components such as capacitors and resistors.
Post time: Oct-30-2023