GB937320A - Improvements in or relating to encased magnetic cores - Google Patents

Abstract

937,320. Transformers and inductors. TELEGRAPH CONDENSER CO. Ltd. Sept. 12, 1961 [Sept. 14, 1960], No. 32674/61. Class 38 (2). An encased toroidal magnetic core has a central tubular non- magnetic section, with a winding of magnetic material thereon one or both ends of the tubular section, being deformed as in Fig. 5, to surround the winding. In the first embodiment (Fig. 5) a tube 14 of heat-resistant non-ferromagnetic material, such as stainless steel, is wound with the magnetic coil 16 and then formed to the required shape. When the coil 16 is annealed to give the required magnetic characteristics, no appreciable distortion of the element 14 occurs, which would stress the winding and alter its magnetic characteristics. The gap between the ends of element 74 is filled with an insulating cement or plastic 25. In another embodiment (Fig. 8) two preformed elements 14A and 14A1 co-operate. The magnetic wire or tape winding 16A is wound on element 14A, and the element 14A1 inserted. The unit is sealed at 25A, 26A. In further embodiments (Fig. 9, not shown, and Fig. 10) the winding 16c is on a single heat-resistant element 14c, and after annealing the unit is sealed with a plastic element 30c, which can be fitted without distorting the element 14c, and stressing the coil. Specification 800,054 is referred to.