Patent GB-873999-A (GB)
Title: Improvements in or relating to analogue computing apparatus
Inventor: MATTHEWS ROBERT
IPC: G06G7/28
Filed: 1959-05-26
Abstract: 873,999. Radar; valve pulse circuits. DECCA RECORD CO. Ltd. May 24, 1960 [May 26, 1959], No. 17978/59. Classes 40(6) and 40(7) [Also in Group XXXVI] An electronic "rotor" which replaces a position indicating device for example a synchro, (see Group XXXVI) is used in interception control apparatus, is shown in Fig. 2 and comprises one C.R.O.34 on which a target position is displayed by radar apparatus and also comprises a target follower unit 43 to provide output voltages representing the components in two orthogonal directions of the speed of the marker and target. The interception is controlled from a C.R.O.50, connected to the outputs from unit 43 by switches 57 to provide a marker trace on 50 following the target. The target marker trace is a straight line so that its end represents the future target position. The interceptor course is determined by manually adjusting the interceptor direction control unit 88, and by adjusting a voltage source 89 to initiate a pulse from comparator 90 to start the "J line", i.e. the interceptor attack line trace, and also the display trace corresponding thereto. The direction of the J line trace will continue in a fixed direction until a start of turn pulse from comparator 81 sets rotor circuit 83, controlled by 88, into operation when the trace direction will change at a rate determined by the rotor frequency. The rotor outputs provide two inputs to a double coincidence comparator 87 (see below) the other two inputs of which are provided by voltages corresponding to the final direction of interception and provided by the output voltages of a rotor circuit 60 representing the sum of the angle of attack and of target speed (derived from target follower 43) set into rotors 60, 61 respectively. When the inputs to the comparator 87 are equal, the turn of the interceptor path will be discontinued and the straight line trace for the final attack will be produced by switching electronically the C.R.O. wave from generators 53, 54 directing to the outputs from a staticiser 70 (connected in turn to the rotor 60) which controls the generators for the final attack path. The attack angle and range will be set into rotor 60 and unit 86 respectively manually and adjust the frequency of the rate of turn rotor 83 to the required rate for the interceptor. The apparatus is then switched to the trial position in which source 89 is controlled manually and a trial course is set in. The controls are then adjusted so that the end of the interceptor marker trace coincides with that of the target trace produced automatically on 50 and the interceptor subsequently controlled to fly along this course. Double coincidence comparator (Fig. 4). A D.C. coupled comparator comprises two pairs of valves 100, 101 and 102, 103 arranged as longtailed pairs, a first voltage and a reference voltage being applied to valves 100, 101 respectively and a second voltage, to be compared with the first, and a further reference voltage to valves 102, 103. The valve anodes are respectively connected to the anodes of four diodes 104-107 and the cathodes thereof to a Schmitt trigger circuit 108. If both long-tailed pairs have equal inputs to the two valves, the anode potentials thereof will fall sufficiently to apply an input signal to the trigger circuit. Specifications 737,519, 837,201 and 867,361 are referred to.