Patent GB-404014-A (GB)
Title: Improvements in or relating to electric signalling systems
IPC: H02J13/00
Filed: 1932-07-06
Abstract: 404,014. Electric signalling and remote-control systems. AUTOMATIC ELECTRIC CO., Ltd., Strowger Works, and GUNNING, P. F., 10, Fairfield Street, Fairfield, both in Liverpool. July 6, 1932, No. 19123. [Class 40 (i).] In an electric signalling and remote control system in which a number of sub-stations are connected to the main station over a single pair of line wires, the receiving relays at the substations are bridged across the line wires in series with neon tubes and the signals from the main station are transmitted at a potential high enough to strike through the discharge tubes whilst signals from the remote stations are transmitted at a lower potential which affects the main station receiving equipment only. Station selecting pulses are of alternating current whilst direct current pulses of positive and negative polarity are used to control the apparatus in the sub-stations. Apparatus at all sub-stations can be operated simultaneously if required. The switches at main and substations are stepped by reciprocal control, the return pulses serving to set supervisory equipment at the main station. The actual control pulses may be of longer duration than the purely stepping pulses and telephone facilities are provided. Uncontrolled movement of apparatus is signalled back automatically to the main station and faults are also notified. General operation. The depression of a control key at the main station (Figs. 1, 2, 5, 6) initiates the transmission of a single train of impulses, comprising alternating and rectified current pulses, which steps switches at all the sub-stations in turn, the particular pieces of apparatus to be operated being controlled when connection thereto is established. A single A.C. pulse is first sent, which steps switches at all sub-stations onto their first contacts, and this is followed by a series of rectified pulses which control the apparatus at the first substation only. When the first sub-station switch has completed its cycle a second A.C. pulse is transmitted which steps the switches at all but the first station and the following rectified train controls the second station apparatus. A third A.C. pulse puts the third station equipment into cormection with the control wires and this cycle continues until all switches at all sub-stations have been set. Apparatus at all sub-stations can be simultaneously controlled by the transmission of a single rectified pulse. The apparatus at a single sub-station only is shewn in the drawings. Selection of circuit breaker. To operate a circuit breaker the relative locking control key (Fig. 2) is depressed and the non-locking start key (Fig. 1) is operated. Magnet ACM and relay AL pull up and when the start key is released, ACM falls away to step ACS onto its second contact. Off normal springs ACSN1 change over and IMP pulls up. Relay CO energizes and opens the circuit of IMP but during the slow release period of IMP, relay AC is energized, over 2a of ACS, and connects alternating current from 12, 13 over wires 10, 11 to the sub-stations. The neon tubes at the sub-stations strike and polarised relays DR and OR energize. Relays D and O operate and magnet SRM pulls up. Relay IRL energizes and holds during the impulse train. At the main station the pulse lamp (Fig. 1) flickers and the circuit of RL is maintained to hold open the fault alarm circuit. When the pulse ceases the sub-station switches step to their second consense to energize DR only at all sub-stations. The wiring of 1c (Fig. 3) differs at all sub-stations, the contacts connected to IRL commencing at the second contact at the first sub-station, at tacts. Relay M (Fig. 4) energized when IRL pulled up and, when SRS stepped to its second position, N (Fig. 4) energized and the circuit of M was broken. During the slow period of M a pulse of 50 volt current is returned to the main station of such sense as to operate Q. The voltage being low enough not to strike the neon tubes at the sub-stations. Relay Q brings up OUT, CO is shorted down and ACM is reoperated over ACSN1. SA pulls up over 3a and locks, lighting the first sub-station progress lamp in series with relay P. When the signal back pulse terminates ACS steps to its third position and IMP and CO re-operate. In the third position of 2a either OP or PU is energized, depending on the position of the connected control key. It is assumed that the key is normal, as shewn, and consequently PU pulls up and the pulse delivered by AC during the slow period of IMP is of direct current of a the third contact at the second sub-station and so on, the second contact at the third substation, the second and third at the fourth substation, and so on, being wired to the first contacts. As a consequence of this wiring the operation of one only of the relays DR and OR followed by D or O, is effective at all but the first sub-station to hold IRL only. At the first sub-station however a circuit is completed to re-energize SRM. When the pulse terminates SRS steps into its third position, M re-energizes and whilst N is falling away a return pulse of low potential is returned to re-energize Q at the main station and re-operate ACM as before described. Operation of circuit breaker. It is assumed that the second control key, Fig. 2, is moved to its effective position and consequently when IMP operates with ACS in its fourth position, relay OP pulls up over 2a and the next pulse delivered is of such polarity as to operate relays OR at the sub-stations and the O relays pull up to hold their respective IRL relays. At the first sub-station however relay O, in addition to completing the circuit for SRM, closes a circuit over 14 and 5c to wire 15 which effects the closure of circuit breaker No. 1 (not shewn). Relay OP moreover closes an additional holding circuit for IMP (Fig. 1) and also completes a circuit for slow operate relay X which in turn brings up Y. Y operates slowly and when fully energized breaks the circuit of X and X falls away slowly. When X has released, IMP commences to fall away and then OP de-energizes to remove the pulse from the signalling line. A pulse 2 three times the normal length is thus delivered to ensure the circuit breaker operating fully. When the pulse terminates SRS steps and M and N deliver a return pulse to the main station. Supervisory signals. Each circuit breaker is provided with contacts, such as CBC1-CBC5, which follow the movement of the circuit breaker, and in addition each circuit breaker is supervised by a magnetic locking relay such as relays 1LA-5LA, which may be of the horseshoe type with both poles wound, the relays being energized by current flow in one direction, holding by permanent magnetism, and deenergized by current flow in the opposite direction. As the switch SRS is stepped in synchronism with the main station switch, relay RV is connected over 6c to one side of the circuit breaker contacts CBC. If the particular breaker tested is closed, RV energizes and the return pulse delivered by M and N is reversed in polarity to bring up relays I and IN in the main station, the latter relay, in addition to completing the circuit for ACM, energizing the relative supervisory relay such as LA, LB, LC, to control the condition of the indicator CB lamps shewn in Fig. 6. The relays LA, LB etc. are similar to the relays 1LA etc. and are energized by relay IN and released by relay OUT. Moreover the sub-station supervisory relays ILA etc. are connected to the control leads over 2c and 3c and are operated by the outgoing pulse to set in accordance with the position of the circuit breakers. Supervisory signals may be transmitted in respect of circuit breakers not controlled from the main station and in the example illustrated five circuit breakers are contemplated at the first sub-station of which only one is remotely controlled. The contacts of 2a of ACS relating to non-controlled circuit breakers are wired directly to PU so that as ACS steps, pulses are delivered to operate DR only and step SRS. Selection of further sub-stations. When all the circuit breakers of the first sub-station have been connected with, wiper 2a of ACS reaches contact 13 and relay AC is operated to deliver an alternating current pulse to the sub-stations. At the first sub-station, wiper IC of SRS has moved clear of the bank commoning so that this, and further pulses, are effective only to hold IRL. At other substations however relays D and O complete circuits over wipers 1c of SRS in their second positions to move them into position. 3. A series of rectified current pulses is then transmitted and the apparatus at the second sub-station only is affected. When the second substation switch has moved clear of its bank commoning, a third alternating current pulse is delivered to bring the third sub-station equipment into operation and this cycle continues until all sub-stations have been connected with, a series of switches ACS-ZCS being used in turn at the main station. Resetting of apparatus. When the full impulse train is completed ABS is energized over 2b of ZCS and ZCS homes. At the substations relays IRL release and the switches SRS home by self-interruption. The operation at the main station operates key RLSE, the progress lamps, which indicate the stations connected, are extinguished and the alarm ALB, which operates whenever P is energized, is released. Fault signals. Should the signal train be interrupted, relay RL releases and closes a circuit over 4a or 4b for one of the alarm relays FA-FD, which locks to the key SFR. The relative station fault lamp lights in series with the alarm relay P and the operated switches ACS-ZCS are returned to their home positions. When the fault has been noted the alarm signal is disconnected by the momentary operation of SFR. Signalling automatic movement of circuit breaker. When a circuit breaker trips on overload, or otherwise alters its condition, a circuit is completed for