GB473753A - Improvements in or relating to electric systems for controlling the position of a controlled object - Google Patents

Abstract

473,753. Electric control systems. SPERRY GYROSCOPE CO., Inc. Feb. 15, 1936, No. 4647. Convention date, Feb. 16, 1935. [Class 40 (i)] In an electric remote control system of the resultant field type, disagreement between the positions of the controlled and controlling means during operation is eliminated by introducing into the system a correcting signal which depends upon the acceleration or deceleration of the controlling means with respect to the controlled object. As shown in Fig. 1, a hand wheel 1 controls the position of a polyphase rotor 4 in an alternating field produced by a stator 6. Movement of the rotor 4 causes a corresponding angular shifting of the magnetic field in the rotor 9 of the receiver, the rotor co-operating with a stator winding 11 in such a manner that the induced voltage varies between zero and a maximum according to the position of the field in the rotor. The output of the winding 11 is divided between two circuits 60, 20 the former of which produces an e.m.f. proportional to the angular displacement between the rotors 4, 9 whilst the latter produces an e.m.f. proportional to acceleration. These e.m.f's. are combined in the output of the transformer 58 and effect operation of the motor 14 and controlled object until the rotor 9 driven by the motor is moved into the position of zero voltage in the winding 11. The circuit 20 is connected 'to a transformer 19 the output of which is applied to phase detector tubes 23, 24 arranged so that current flows in the output circuit of one or other tube depending upon the phase relation of the signal, i.e. upon whether the hand wheel is turned in one or other direction. The output of the tubes is passed through a filter 36 .. 40 and is applied as a unidirectional e.m.f. to a condenser 41 connected in series with a transformer 48. The arrangement of condenser 41 and transformer 48 serves as an acceleration or deceleration detector, and the output of the transformer 48 is applied to oppositely connected modulator tubes 44, 45 which supply a transformer 52, the secondary of which is connected in the circuit 60 and together with resistances 66, 62 and transformer 58. forms a bridge circuit. The displacement signal supplied from the stator 11 and applied directly to the circuit 60 is additive to the signal corresponding to acceleration and derived from circuit 20. The output of the transformer 58 is applied through amplifiers 71, 72 and rectifiers 79, 80 to the control windings of a repulsion motor 14 which operates a controlled object 2 and also rotates the rotor 9. In a modification, the repulsion motor is replaced by an A.C. series motor.