GB966247A - Electrical inductive apparatus - Google Patents

Abstract

966,247. Transformers. WESTINGHOUSE ELECTRIC CORPORATION. Dec. 28, 1961 [Jan. 5, 1961], No. 46484/61. Heading H1T. An electrical inductive apparatus, on which there is at least one winding 30, Fig. 1, has two magnetic core sections 32, 34 formed from two different magnetic materials such that the coercive force of core section 34 is several times larger than that of the other, the winding being disposed so that when current flows therethrough a magnetic flux is produced in both of the core sections. Alternatively, the cores 82, 84, Fig. 4, may be of similar materials, and in a further modification, Fig. 12 (not shown), separate transformers may be employed. Each of the core sections 34, 84 has one or more gaps 36, 86 filled with a non-magnetic substance such as air. One of the core sections may be made of sheet material having a first preferred direction of orientation lengthwise of the sheet and a second one perpendicular to it while the other core section may be made of sheet material having only a lengthwise preferred direction of orientation. A transformer having such a composite core has smaller core losses and compensates for unmatched characteristics of semiconductor devices in circuits such as a two transformer inverter, Fig. 10 (not shown). It may also be used to prevent gradual saturation of the magnetic core structure in half-wave rectified circuits. Additional windings may be provided on the individual core sections so that the magnetic characteristics of each can be measured; the winding on the core section having a low coercive force can also be used as a constant voltage source provided that part of the core is saturated.