GB441219A - Improvements in or relating to a remote control system for a reversible follow-up motor - Google Patents

Abstract

441,219. Electric control systems. SPERRY GYROSCOPE CO., Ltd., Great West Road, Brentford, Middlesex.-(Assignees of Riggs, A. S.; 160, Central Park South, New York, U.S.A.) Sept. 6, 1934, No. 25702. Convention date, Sept. 9, 1933. [Class 40 (i)] In a system in which movement in one of two directions is controlled by an alternating current varying in magnitude and direction, a single electron tube, such as a grid glow tube is used, the input to the tube being switched alternately to two points in the control circuit whilst the output is connected in synchronism alternately with the two windings of the responding device. The invention is described as applied to a follow-up mechanism having a reversing motor and two follow-up mechanisms operated through a single tube. In the followup system shown in Fig. 1, which is applied to a gyro compass, movement of the armature 15<1> affects the current flow in transformer 16. The output of the transformer is fed through distributer 21 to the valve 17, the output of which is fed through valve 30 and distributer 22 to the reversing windings of motor 35. The distributers 21, 22 and the generator 8 are connected, as by shafts 40, 40<1>, so that the cut-over takes place when the current is zero to prevent sparking. By means of resistances 26, 27, the tube 17 is given a phase line voltage, which is added vectorally to the signal voltage. A voltage of gradually shifting phase is thus applied to the grid of tube 17 to make it alternately positive and negative. When positive, plate current passes and tube 30 becomes inoperative ; when negative the plate current becomes zero and tube 30 becomes conductive. Hence current is fed to the motor windings 36, 37 in synchronism with the movement of the distributers and varies in magnitude depending on the position of the armature 151, the motor being driven accordingly. Condensers 42, 43 smooth the half-wave rectified current and resistance 44 limits the motor current. The motor is arranged to oscillate slightly when the armature is centrally placed. In the arrangement shown in Fig. 2, the distributers have four sections so that two motors can be controlled by two inputs through a single valve. Reference has been directed by the Comptroller to Specification 371,824.