GB381554A - Improvements in or relating to voltage regulators - Google Patents

Abstract

381,554. Regulating transformers. BRITISH ELECTRIC TRANSFORMER CO., Ltd. and WHISH, A. C., Hayes, Middlesex. June 23, 1931, No. 18171. [Class 38 (ii).] In a voltage regulator for use with a transformer, and in which a rotatable regulating winding is engaged by an endwise moving contact, connection to an end of the winding is made through a slip-ring mounted on the same former, and means are provided to reduce the current induced in the ring to a permissible value. As shown, a winding 1 of conducting strip surrounds the main windings 3, 4 and core 5 and is carried by an insulating cylinder 2 rotatably mounted on ball-bearings between insulating endplates 10 separated by tie-rods 12, 12a, 12b. The moving contact 15, Fig. 5, is resiliently carried by a crosshead 16 which slides along the tie-rods 12a, 12b, under the control of a screw-threaded rod' 17 carrying pinions 7a, 8a which mesh with toothed wheels 7, 8 carried by the cylinder 2, the gear ratio being such as to keep the contact continually in engagement with the winding as the control rod 17 is rotated. Alternatively, the rod 17 may be dispensed with, and the contact 15 engage a helical groove in the winding 1. Electrical connection is made with the contact 15 by spring contacts 19, 20 which bear against the tie-rods 12a, 12b. The lower end of the winding 1 is free, and the upper end terminates in a split ring which engages two spring-urged contacts 12, 13a carried by a bridge-piece 14, and electrically connected by a small impedance, one of the contacts 13, 13a being connected with a main winding of the transformer. Alternatively an unbroken ring of high impedance engaging a single contact may be used. The control rod 17 may be operated automatically or by hand, and the control rods of a plurality of such regulators applied to a polyphase transformer or to a number of transformers may be mechanically coupled.