1,044,493. Transformers. WESTINGHOUSE ELECTRIC CORPORATION. March 25, 1965 [May 25, 1964], No. 12692/65. Heading H1T. A current or other transformer or inductor has a magnetic circuit formed of a magnetic powder preferably carried by a liquid or gas and moving relatively to the windings. The magnetic fluid 4 is driven through the conduit 2 by a circulator 3 and is cooled in a heat exchanger 11. The fluid may comprise powdered ferrite in oil and the windings 12 may be disposed additionally or alternatively inside the conduit. There may be a plurality of flow paths, circulating devices and heat exchangers or the conduit may form a single closed loop.