Method and apparatus for measuring an alternating current

摘要

The apparatus comprises a rectifier bridge 12, a circuit 1 for delivering two pulse signals I<A>, I<B>, the pulses and the peaks of the rectified AC being concomitant. Two analogue circuit breakers 2, 3 are controlled by the signals I<A>, I<B>. Two capacitors 4, 5 are connected to the circuit breakers 2, 3 and a circuit 6 - 10 calculates the half-sum of the output signals from the capacitors 4, 5. Application to the protection of electrical installations by determining the amplitude of a fault current before it becomes established. <IMAGE>