A varistor is an important electronic component that is made using the nonlinear voltage-current characteristics of semiconductor materials. It is voltage-sensitive, meaning its resistance changes with the variation in voltage. Varistors belong to the category of semiconductor components and play a crucial role in electronic product design and applications. When and why were varistors invented?
Varistors were invented in the 1920s to 1930s, a period marked by rapid advancements in electronic technology and the creation of numerous electronic devices. As electronic devices became increasingly prevalent, protecting them from the effects of high voltage became a significant concern.
Many electronic devices operated using high voltage power sources, such as X-ray machines, radars, and telegraphs. These high voltages posed a threat to both the devices and the safety of users. Consequently, there was a need to develop a component that could automatically disconnect the circuit under high voltage conditions, thereby safeguarding the electronic components for both users and devices. Varistors were born in response to this demand.
In electronic circuits, when an overvoltage occurs, varistors withstand the excess voltage and perform voltage clamping, absorbing the surplus current to protect subsequent electronic components and the circuit.
As electronic technology advanced, the applications of varistors gradually expanded. For instance, in the automotive industry, varistors are widely used in airbag control systems. Since airbags need to inflate rapidly to effectively mitigate the impact of collisions, varistors work in synergy with the airbag system by controlling the current. Additionally, in the field of electronic products, varistors are commonly used in various signal input circuits. When the input voltage exceeds a certain threshold, the resistance of the varistor changes, allowing it to adjust its resistance to an appropriate value. This helps keep the circuit voltage within the operational range, protecting electronic devices and components from damage caused by overvoltage.
This article is provided by JYH HSU (also Dongguan Zhixu) Electronics, an original manufacturer of capacitors and resistors based its factory in mainland China.
Post time: Jun-12-2023