GB259215A - Improvements in and relating to means for reproducing position - Google Patents

Abstract

259,215. British Thomson-Houston Co., Ltd., (Assignees of Nixdorff, S. P.). Sept. 29, 1925, [Convention date]. Controlling motors to follow distant movements.-In controlling a motor, which may train a search-light, to follow the movements of a distant instrument such as a telescope by an arrangement of induction devices which impress on the motor a voltage proportionate to the angle of lag, means are provided for automatically reducing the rise of voltage while the motor is accelerating and increasing the fall of voltage while the motor is slowing down, in order to increase the accuracy of the control. In the arrangement described an angularly movable coil 15 operated by the telescope 11 and carrying single-phase alternating current acts through interconnected armature windings 14, 19 to generate voltage in a movable coil 18 operated by the motor 12 in conjunction with the search-light 10. An electron discharge tube 22 amplifies the output of the coil 18 and delivers it through a pair of rectifying and further amplifying electron tubes 24, 25 to the field of a small motor-driven direct current generator 38 serving as exciter to a larger motor-driven generator 44 which feeds the working motor 12. According to the invention the armature winding 19 during the run of the motor is first moved forward and afterwards back again over a limited angle by differentially acting magnets 54, 55, the direction and magnitude of the movement changing with the change of impressed voltage from the coil 18. The effect is to decrease the acceleration and shorten the period of slowing-down. Specification 247,087 is referred to.