A current transformer comprising a

A current transformer comprising a tubular main insulator, a number of first windings arranged around the main insulator, and a number of second windings arranged inside the main insulator. The second windings are arranged opposite their corresponding first windings so that the pairs of windings formed in this way are, in the direction of the axis of the main insulator, at a distance from each other. The primary windings are connected in series. A magnetic circuit related to each pair of windings consists of a first core portion that surrounds each first winding from the outside and has yoke portions, and of a second core portion covering each second winding and the main insulator from the inside and has likewise yoke portions. The subsequent cores, or core portions, have common intermediate yoke portions and the primary windings are arranged so as to magnetize both cores in the same direction