GB896856A - Digital input automatic transmitter - Google Patents

Abstract

896,856. Electric selective signalling systems; electric positioning systems. BENDIX CORPORATION. March 17, 1960 [March 24, 1959], No. 9510/60. Class 40 (1). In a shaft positioning system a bridge ABCD, Fig. 1, compares an input (which partially determines the position of a shaft AD 124) in the form of a ratio - of two arms of DC the bridge with the outputs of a selsyn 24 driven by a servomotor 69 which also drives shaft 124. The discrepancy between the two inputs to the bridge is passed via a tachometer 117 (providing an anti-hunt signal in known manner) and an amplifier 77 to drive the servomotor to minimize the discrepancy. However, the selsyn provides outputs on lines 25, 26, 27 whose maximum to minimum ratio determines the position of its rotor 65 only inside a 60 degree segment. A switch arrangement 28 is interposed between the bridge and the selsyn to connect lines 25, 26, 27, in three different ways to points A, B, C of the bridge, thus arranging that the position of the switch determines which one of three 60 degree segments contains the selsyn rotor. However, still only 180 degrees out of 360 degrees is covered. A reversal switch 80 (i.e. having two states) inserted between the bridge 10 and the amplifier 77 determines which 180 degree is selected by being in one state or the other. Thus the input to position the shaft within 360 degrees comprises a manual movement of arm 18, and the manual setting of switches 28 and 80. A complete schedule is given in the Specification. In a modification, a punched tape input is used to operate through relays (214, 216, 218, Fig. 3, not shown), a resistance box to set the AD arm ratio - of the bridge and to determine DC by the energization of relays the state of switches 28 and 80.