GB664065A - Improvements in electrical measuring and control systems - Google Patents

Abstract

664,065. Electric signalling systems. METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. March 11, 1949. [March 16, 1948] No. 7903/48. Class 40 (i). [Also in Group XXXV] In a measuring or control system an inductive device comprises magnetic members ST, R, provided with primary and secondary windings P1-P4, S1-S4 and with windings A1-A4, B1- B4, which produce a torque opposing any produced by the controlling means, such as a gyro G. The primary P1-P4 is energized from 10, 11, by A.C. of comparatively high-frequency and any displacement of the rotor R causes a current to flow in the secondary S1-S4, and a signal is applied to the grids of push-pull valves V1, V2, which may be normally conducting. The anodes of valves V1, V2, are energized by transformers from the same A.C. supply and their circuits include the windings A1-A4, B1-B4, which (or one of which) if V1, V2, do not normally conduct) thus produce a torque tending to eliminate the displacement. A control or indicating output is derived at 22, 23. The winding A1-A4, B1-B4, may alternatively be energized with A.C. of frequency the same as, or different from, that applied at 10, 11. A phase-advancing network (not described) is connected in the amplifier output to reduce hunting. Under all working conditions, the magnetic circuits of ST and R remain unsaturated.