GB612442A - Improvements relating to voltage regulating apparatus for alternating current circuits - Google Patents

Abstract

612,442. Automatic regulation. WESTING- HOUSE BRAKE & SIGNAL CO., Ltd., and WALKER, A. H. B. April 18, 1948, No. 12020. [Class 38 (iv)] . The invention relates to a voltage regulating system of the general type described in Specification 548,526, comprising two transformers T1, T2, having their secondaries connected in opposition and of which one, T2, works at a high saturation density, with a tuned circuit L1, Cl connected across the output. In the present invention, compensation for voltage changes resulting from frequency variations is provided by varying the saturation of autotransformer T2 by a unidirectional current derived from the supply. Transformer T3, connected across the input leads 1, 2, supplies a rectifier V and saturating winding 5 through a circuit C2, L2, tuned above the maximum possible supply frequency so that the current fed to winding 5 increases with rise in frequency. Instead of the combination L2, C2, a rejector circuit may be connected across the secondary of T3 and tuned below the lowest possible supply frequency to produce the same effect. Transformer T3 may alternatively be connected across the output as described with reference to Fig. 2 (not shown). This modification also shows the control current from rectifier V passed through the two windings of transformer T2 in series instead of through a separate saturating winding. In this case, condensers in the lower common connection of the transformer windings allow the supply currents to pass, but prevent short-circuiting of the control currents. Specifications 584,420, 597,371 and 608,108 also are referred to.