The invention concerns a device wherein a magnetic field produced by a primary winding (1) passed through by the current (i1) to be measured is balanced by an opposite magnetic field produced by a secondary winding (2) passed through by a compensating current (i2). The device comprises means (3) sensitive to the field resulting from the addition of said opposite magnetic fields to regulate in closed loop the compensating current (i2). The invention is characterized in that the sensitive means (3) is sensitive only in the direction of the resulting field and controls in reverse the inversion of the direction of flow of the compensating current (i2) in the secondary winding (2). Said sensitive means (3) can consist of a Hall-effect sensor with bipolar output signal. The invention is applicable to measurement of a current in an electronic motor vehicle.
