Patent ID: 6788046
Filing Date: 2004-09-07
Classification: G01R

Abstract:
A compensation current sensor in which the magnetic field, generated in a magnet core by a primary winding through which flows the current to be measured, is compensated by the compensation current in a secondary winding, wherein, to control the compensation current, at least one magnetic field probe affected by the magnetic field and located in the area of the secondary winding records deviations from zero flux and supplies this measured value via an evaluation circuit to an amplifier arrangement to generate the compensation current while, at the output of the amplifier arrangement, the secondary winding is connected in series to a terminating resistor so that a voltage proportional to the current to be measured is present at the terminating resistor wherein means are provided which couple a part of the magnetic flux of the primary winding, said magnetic flux not coupled into the magnet core, into the compensation apparatus formed by the secondary winding and magnetic field probe and simultaneously back-couple the magnetic leakage flux of the secondary winding into the compensation apparatus and that the core cross-section of the magnet core is greater in a first section located in the area of the compensation apparatus than in a second section of the magnet core.