GB424920A - Improvements relating to trunk communication cables, in particular for the transmission of high frequency currents - Google Patents

Abstract

424,920. Electric cables. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. Feb. 22, 1934, No. 5880. Convention date, Feb. 22, 1933. [Class 36] In order to prevent mutual interference between different " double conductors " i.e. conductors comprising out and return elements, the two elements are so arranged that their " electric axes ", i.e. the loci of the centroids of their cross-sections, are coincident and the pair are enclosed in a sheath of magnetic material. Fig. 1 shows an arrangement of four such double conductors, each consisting of two concentric conductors 31 .. 34, separated by an air space and a spiral cord 35 and enclosed in insulation 36 and a magnetic sheath 37. The sheaths 37 are in electric contact with each other and an enclosing sheath 38, but may be insulated. The air space and cord 35 may also be replaced by solid insulation. Fig. 3 shows an arrangement where each element of each double conductor consists of two conductors in parallel, the conductors 53, 54 of one element being situated at opposite angles of a square and the conductors 55, 56 of the other element at the other two angles. The magnetic sheath should be of material of high resistance and high permeability, it may be divided transversely, or may be made of powdered material applied to a strip of paper &c. wound helically about the conductor.