METHOD FOR OPERATING A FAULT-CURRENT CIRCUIT BREAKER, AND FAULT-CURRENT CIRCUIT BREAKER

摘要

In a fault-current circuit breaker (10), the principle of controlled inductance is used: a secondary coil (30) is exposed to pulses from a square-wave generator (40). According to the invention, the pulse height of the square pulses output by the square-wave generator (40) varies in order to regulate the current flowing through the secondary coil (30) in such a manner that the time derivative of the amperage has a constant magnitude. If the voltage is now measured at two ends (32, 36) of the secondary coil (30), said voltage is directly a measure of the inductance of the secondary coil (30), and any fault current can be deduced therefrom.