GB868398A - Improvements in and relating to computing apparatus - Google Patents

Abstract

868,398. Electric analogue calculating systems. KELVIN & HUGHES Ltd. July 17, 1959 [April 17, 1958], No. 12275/58. Class 37. In an arrangement for computing the range x, and bearing α of a target with respect to an aircraft from the range R, and bearing 6 of the aircraft with respect to a ground station, and the range D and bearing # of the target with respect to the station, the apparatus includes a resolver 3 having a pair of high-impedance windings 8, 9 and a pair of low-impedance rotor windings 14, 15, resolvers 1 and 2 for providing signals R cos #, R sin # and D cos #, D sin #, whereby signal R cos # + D cos # is applied to winding 8 and R sin # + D sin # to winding 9, and a servomotor 22 whereby the rotor of resolver 3 is driven to a position in which the magnitude of the signal induced in winding 15 is zero. A 400 c.p.s. carrier, amplitude modulated in accordance with range R, is applied through a cathode follower stage 16 to stator winding 4 of resolver 1 the rotor of which is set to position #, and a signal corresponding to D is similarly applied to resolver 2 a further 400 c.p.s. input 42 being provided for calibration purposes. The output from rotor winding 14 of resolver 3 drives a servomotor 25 through a comparator 23 the other input to which is provided from sources 26, 27 in quadrature through potentiometer 24 the wiper of which is driven by the servomotor 25. The servomotors 22 and 25 also drive a roller blind type indicator carriage and a roller blind indicator respectively.