Patent ID: 8299779
Filing Date: 2012-10-30
Classification: G01R

Abstract:
1. A device ( 1 ) for measuring an intensity (I) of an electric current, the device comprising at least one magnetic circuit ( 3 ) located near an electric conductor ( 2 ) traversed by a current to be measured for channeling a magnetic field induced around the conductor by the current to be measured, at least two electric coils ( 4 ) associated with the magnetic circuit ( 3 ) for delivering a voltage proportionate to a derivative of the intensity (I) of the current to be measured, and at least one module for processing the voltage to deliver a value for the intensity measured, the magnetic circuit ( 3 ) being open and defining at least two gaps (E), each gap (E) being closed by an electric coil ( 4 ) such that the magnetic circuit ( 3 ) and the electric coils ( 4 ) define a closed path (C) for circulation of the magnetic field, and the coils ( 4 ) disposed in the gaps (E) occupying more than one third of the closed path (C) characterized in that the coils ( 4 ) disposed in the gaps (E) are made from printed circuits ( 40 ) comprising windings ( 41 ) engraved on a substrate, the windings ( 41 ) comprise a plurality of loops and each of the loops comprises an upper line ( 41 a ) and a lower line ( 41 c ) which are supported on opposite surfaces of the respective substrate, ends of the upper and the lower lines ( 41 a , 41 c ) are coupled by return lines ( 41 b , 41 d ) with one of the return lines ( 41 d ) coupling adjacent loops, at least portions of the upper and the lower lines ( 41 a , 41 c ) of the loops extend parallel to each other and perpendicular to a direction in which the magnetic field circulates, and in that the coils ( 4 ) are identical, attached in opposition and electrically connected in a series, so that their useful fields are increased and their parasitic fields are canceled.