GB548926A - Improvements in electrical acceleration and/or deceleration governing means - Google Patents

Abstract

548,926. Automatic control systems for winding apparatus &c. SMITH, G. D., HILL, E. P., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. June 16, 1941, No. 7610. [Class 38 (iv)] Speed.-Acceleration and retardation are controlled by applying to the primary winding of a transformer M1 a D.C. voltage proportional to the speed and connecting one secondary of the transformer to the control coil A of a compounding exciter GE of the magnetic bridge type as described in Specification 491,743, a metadyne or other means whereby a rapid development of output or trigger action is obtained for controlling the operation of speed control mechanism, such as a torque-motor MA releasing, applying or controlling a brake, either directly or through a fluid pressure or other servomotor. The tachometer generator GA is connected through a rectifier DR1 to the transformer MI to eliminate the factor of direction of motion. If it is desired to control acceleration or retardation separately a rectifier is included in the secondary circuit. Hunting may be checked by a rheostat coupled to the speed controlling mechanism and connected in circuit with a field coil of the exciter CE or the like. Fig. 1 shows a braking control in which the torque motor is associated by linkage with a manual brake lever BL, an emergency speed control solenoid ES and a valve BCV operating a servomotor to apply a brake when moved downwardly, the torque motor MA operating against a spring S to relieve the brake.