Jännitesuodatin

Jännitesuodatin, also known as a voltage filter or surge protector, is a device designed to protect electrical and electronic equipment from voltage spikes and surges. These transient overvoltages can be caused by various sources, including lightning strikes, power grid fluctuations, and the switching of heavy electrical loads. When such an event occurs, a jännitesuodatin diverts the excess voltage away from sensitive connected devices, thereby preventing damage or destruction.

The most common type of jännitesuodatin utilizes metal oxide varistors (MOVs). MOVs are semiconductor devices whose resistance changes drastically with voltage. Under normal operating voltages, their resistance is very high, allowing electricity to flow through to the protected equipment. However, when a voltage surge occurs, the resistance of the MOV drops dramatically, creating a low-resistance path for the excess current to flow to the ground. This effectively shunts the surge away from the connected device.

Another type of jännitesuodatin employs gas discharge tubes (GDTs). GDTs contain a gas that ionizes and conducts electricity when a high voltage is applied. Like MOVs, they divert excess voltage to ground. Some advanced jännitesuodatin units may combine multiple protection technologies for enhanced security.

Jännitesuodattimet are widely used in both residential and industrial settings. They are commonly found in power strips, standalone units plugged into wall outlets, and integrated into more complex electrical systems. The effectiveness of a jännitesuodatin is often rated by its ability to absorb energy (measured in joules) and its clamping voltage, which is the voltage level at which it begins to divert current. Regular inspection and replacement of older or damaged units are recommended to ensure continued protection.