spänningsundertryckare

Spänningsundertryckare, often translated as surge suppressors or transient voltage suppressors (TVS), are electronic devices designed to protect electrical circuits and equipment from voltage spikes and surges. These overvoltage events can be caused by various sources, including lightning strikes, power grid fluctuations, and the switching of large inductive loads. A spänningsundertryckare acts by diverting the excess voltage away from the sensitive components it is protecting.

The fundamental principle of operation for most spänningsundertryckare involves a non-linear voltage-current characteristic. Under normal operating voltage conditions, the device presents a very high impedance, effectively acting as an open circuit and not interfering with the regular flow of current. However, when the voltage across the device exceeds a predetermined threshold, known as the clamping voltage, its impedance rapidly decreases. This sudden drop in impedance allows the surge current to bypass the protected circuitry and flow through the spänningsundertryckare, thereby limiting the voltage that reaches the sensitive components to a safe level.

Common technologies used in spänningsundertryckare include Metal Oxide Varistors (MOVs), Transient Voltage Suppressor Diodes (TVS diodes), and Gas Discharge Tubes (GDTs). MOVs are widely used due to their cost-effectiveness and ability to handle high surge currents, though they can degrade over time. TVS diodes offer faster response times and precise clamping voltages, making them suitable for more sensitive electronics. GDTs are effective for very high energy surges but have a slower response time. The selection of the appropriate spänningsundertryckare depends on the specific application, the expected surge levels, and the required protection characteristics.