GB1392615A - Arrangement for transmitting signals selectively to series conne ted receivers - Google Patents

Abstract

1392615 Signalling on trains GERMANY MINISTRY OF TRANSPORT 5 April 1972 15743/72 Heading B7N [Also in Division G4] In a system for controlling the selective uncoupling of railway vehicles, a command message is passed through a chain of seriesconnected receivers each of which modifies the message and passes it on until the modified signal arrives at the selected receiver, whereupon the desired uncoupling is effected. In the embodiment of Fig. 1, the message consists of N 'address' pulses followed by a long interval and then an uncoupling pulse, each receiver decreasing the number of pulses by one until the Nth receiver is reached. The first pulse sets a monostable Ma and passes via lines 22, 23 and gates O3a, A6a, 08 to set a monostable M9. The trailing edge of this pulse sets a bi-stable Ba to enable gate A7a for subsequent pulses. The second pulse passes through gates A7a, 013 znd A11 to set a bi-stable B10 which enables gate A12a through which the second and all subsequent pulses pass to line b and the next receiver. The "address" pulses are followed by a long interval and then by the control pulse. The dwell time of M9 is less than the long interval, so that in the selected (Nth) receiver the last address pulse is suppressed by Ba but B10 is not set: thus the control pulse passes via gate A7a to gate Al5a and control output e. The pulses may be fed in from the other direction on line b (to Mb and Bb) and out on line a or d, the circuit operating as above, since each receiver is symmetrical with respect to lines a and b. The various switching elements in the above may operate electronically, pneumatically or hydraulically.