GB710843A - Improvements in transductor regulators - Google Patents

Abstract

710,843. Magnetic amplifiers. ALLMANNA SVENSKA ELEKTRISKA AKTIEBOLAGET. Oct. 31, 1952 [Nov. 7, 1951], No. 27387/52. Class 40 (4) [Also in Group XXXV] In an automatic control system in which a first transductor maintains the output voltage of a rectifier constant until a pre-determined load current is reached when a second transductor maintains the output current constant at that value, the two transductors have cross-connected auxiliary control windings to sharpen the transition from one regulating mode to the other. A mercury arc rectifier 1 is controlled by phase shift of the grid voltage in accordance with the output rectified at 8 of two series connected transductors 10, 11. Each transductor has a reference winding 12, 13, a main control winding 15, 19, an auxiliary winding 24, 23, and is self-magnetized in accordance with output. The winding 15 is energized in accordance with rectifier load current, the winding 19 in accordance with rectifier output voltage. The voltage appearing across each transductor is rectified at 21, 22 and applied to the auxiliary control winding of the opposite transductor. Hence the unsaturated (operative) transductor tends to maintain the saturated (inoperative) transductor in that condition. In a modification, Fig. 2 (not shown), in which the output voltage of a metal rectifier is controlled by a saturable reactor in series with the rectifier input, the two controlling transductors are connected in parallel and their respective currents are rectified and applied to the cross-connected auxiliary control windings. In a further modification, Fig. 3, in which the two parallel connected transductors 47, 48 are directly in series with metal rectifier 49, the self-magnetization is obtained by passing a rectified component of the load current through windings 54, 57, and the switching effect by passing said component through cross-connected auxiliary windings 55, 56. The connections to the main control transductors are supplied from separate windings on a transformer instead of being connected in parallel to a common supply. Their outputs are separately rectified and applied to either a single winding on a further transductor, or, Fig. 5 (not shown), to two opposed windings.