Heißläuferwiderstände

Heißläuferwiderstände, also known as inrush current limiters or soft starters, are electronic components designed to control the surge of current that occurs when an electrical device is first powered on. This surge, termed inrush current, can be significantly higher than the device's normal operating current and can cause damage to components or trip protective devices like circuit breakers. Heißläuferwiderstände achieve their function by temporarily introducing resistance into the circuit during startup.

Typically, a Heißläuferwiderstand is a thermistor whose resistance decreases as its temperature increases. When power is applied, the thermistor is cold and has a high resistance, limiting the initial current flow. As current flows through the device and the thermistor, it heats up, causing its resistance to drop rapidly. Once the device reaches its operating temperature and the inrush current subsides, the thermistor cools down, and its resistance returns to a low standby value. This process effectively dampens the initial current spike.

These components are commonly found in power supplies for electronic equipment, such as computer power supplies, audio amplifiers, and LED lighting systems, where they protect sensitive circuitry from damaging current surges. They are also used in motor control applications to prevent wear and tear on mechanical components and electrical contacts during startup. The primary benefit of using a Heißläuferwiderstand is improved reliability and extended lifespan of electrical devices by mitigating the stress caused by high inrush currents.