GB611204A - Improvements relating to magnetic field responsive devices - Google Patents

Abstract

611,204. Electric control systems. PURVES CORPORATION. June 17, 1942, No. 8310. Convention date, March 28, 1941. [Class 40 (i)] [Also in Group XXXVI] The core of a flux valve has one or more elongated parts each comprising two spaced parallel limbs so related to the exciting winding that in the absence of an external field component directed along the limbs the cyclically varying flux passes equally and oppositely along the two limbs, the two limbs being encircled by the same coils of the output winding. The core has three elongated magnetically permeable pick-up parts 10, 11, 12 which are radially arranged and each composed of two elongated spaced limbs 20, 21, Fig. 2. Each of the limbs has at its outer end an arcuate strip 13, 14, 15 serving as a magnetic field collector. Output windings 16, 17, 18 surround both limbs of each of the core parts 10, 11, 12. The limbs of the core parts 10, 11, 12 are spaced at the centre by a core 23, which is surrounded by winding 19 excited by alternating current. The output windings 16, 17, 18 are Y-connected to the stator windings of a Selsyn receiver 27, Fig. 3, the rotor winding 28 of which controls a compass indicator 29. A frequency doubler 30 is interposed between the A.C. source and the rotor winding 28. The windings 16; 17, 18 are longitudinally adjustable with respect to their cores to facilitate calibration. Specifications 599,428 and 611,205 are referred to. The Specification as open to inspection under Sect. 91 comprises also a modification in which the core consists of a single plate of magnetically permeable material with four arms at right angles. At the centre is a core 44, Fig. 4 (Cancelled), surrounded by an exciting winding 43 and a cup 45 closing the magnetic circuit. This subject-matter does not appear in the Specification as accepted.