Patent GB-355676-A (GB)
IPC: G08C15/12
Filed: 1930-03-26
Abstract: 355,676. Electric signalling systems. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. March 26, 1930, No. 9696. Convention date, March 27, 1929. [Class 40 (i).] In apparatus for the transmission and reception of a number of measurement values over a single line, distributers at the transmitting and receiving stations are maintained in synchronism by impulses differing from the measurement impulses, but transmitted over the same line. The distributer at the receiving station is arranged to rotate at a slightly greater speed than that of the transmitting distributer, and is held at a neutral position until the transmitting distributer reaches a corresponding position and transmits the synchronizing impulse. Rotating contact members 10 .. 50, whose speeds . depend upon the magnitude of the measurement to be transmitted, are connected in turn through the contacts 11 .. 51 of a distributer 4 to energize during each rotation a relay 6, whose armature closes a charging circuit for a condenser 100. The charging current operates a relay 9 to transmit to the line M a number of impulses of constant length dependent on the speeds of the members 10 .. 50. A rotating member 101, driven from mains U-V, controls a switch 2 by which the current in a coil 103 is reversed and the reversing current rotates a Z-shaped armature 104 on the shaft of a contact member 105 switching in during each revolution a stepping magnet 60 of the distributer 4. When the distributer arm reaches the zero position, a relay 8 is energized and a long synchronizing impulse is sent through the relay 9 to close the ends of the line M for a correspondingly long period. At the receiving station a distributer 43 having rotating arms 430, 431 is driven as at the transmitting station from mains U-V by a rotating member 115 operating a reversing switch and a Z-shaped armature 118 having contact discs 119, 120, 121 associated with the arms 430, 431. The incoming impulses operate relays 107, 109 and a reversing switch 108 by which the charging impulses of a condenser 110 are passed through one of the instruments 12 .. 52 corresponding to the position of the distributer arm 430. At the same time the arm 431 closes through the contact disc 120 the circuit of the corresponding magnet coil of the series 122 .. 152 by which the instrument is released to record the incoming impulses. When the distributer arms reach the zero position a circuit is closed through a relay coil 123 actuating through its armature 124 a pawl which arrests the rotation of the member 115. During the transmission of the measurement impulses the coil 129 is energized for longer periods than the coil 128 and the armature 126 assumes the position shown in full lines. On the arrival of the long synchronizing impulse applied to the coil 128 the armature is operated and breaks at the contact 125 the circuit of the relay 123 thus allowing the member 115 to resume rotation. If at the transmitting station the alternating potential fails the step magnet 60 is switched off, and the relay 7 opens the circuit of the relay 6 so that impulses cannot be transmitted to line. On the return of the driving potential the distributer 4 is stepped until the transmission of the synchronizing impulse operates the relay 8 whose upper contact closes the circuit for the relay 7 which closes for itself a holding circuit. At the receiving station the distributer has moved round until it reached the zero position, when the rotating member 115 is held until the arrival of the synchronizing impulse. If at the receiving station the driving potential U-V fails, a relay 55 opens the circuit of the stepping magnet 114, and a relay 66 opening the circuits of the magnet coils 122 .. 522, thus holds fixed the instruments 12 .. 52. On the return of the driving potential the distributer is stepped to its zero position, and the member 115 is then held until the arrival of the synchronizing signal which moves the armature 126 to close a contact 141 through which the relay 66 is again energized. At the same time the circuit of the relay coil 123 is opened allowing the member 115 to resume rotation, and the distributer 43 to run on.