Patent GB-263926-A (GB)
Title: Improvements relating to electric remote control systems
IPC: H02J13/00
Filed: 1925-10-05
Abstract: 263,926. Coventry Automatic Telephones, Ltd., and Smart, N. C. Oct. 5, 1925. Selective distant control systems; tell-tale apparatus.-In a system for controlling and supervising from a remote point, the operation of apparatus units, such as circuit breakers, at a number of substations which are connected across a common group of line wires, a substation before signalling to the control station tests the line wires to ascertain whether the wires are in use for signalling from another station. If the lines are found to be in use, the signals from the testing substations are withheld and the test is periodically repeated until the lines are free. Means are also provided whereby a fault on the control gear at a substation such as the blowing of a fuse is indicated at the control station. Fig. 2 shows the apparatus at the control station and Fig. 3 the apparatus at a substation. The control station is provided with keys, such as 101, 102 for selectively operating the circuit breakers 330, 331 the condition, of which is indicated by supervisory lamps 103 - - 106. Each substation is connected across common lines 138 - - 143 leading to the control station, the lines 138, 139, 140 being used for selectively controlling the units and the lines 141 - 143 for transmitting supervisory signals. The apparatus is selected and controlled by an impulse code comprising three characteristic trains of impulses, the first of which selects the substation and the second and third operate appropriate searching relays in the groups 327, 328 - - -, 325, 326 - - - respectively in order to select a particular unit. Similarly, the signalling lamps at the control station are selected by three impulse trains which are characteristic of the changed condition of the apparatus units. When a particular control key is operated, a. supervisory check of the selection is transmitted back to the control office after the corresponding selection has taken place but before the selected unit is operated. If the selection is correct, a further impulse is automatically sent over the control lines to effect the desired operation. Relay registers A, B, comprising groups of relays 107 - - 112, 301 - - 306 respectively are provided at each station, the register being first set in accordance with the substation to be selected and then in accordance with the unit to be operated. Each train of impulse restores the register A to normal and operates the relays of the register B in sequence up to a point determined by the number of impulses transmitted in such a manner that the selecting relays are successively operated to prepare the control circuit. The units at the substation may be operated automatically and some of the units may be controlled locally, in which case supervision alone is provided for. Selection of a substation. When a key associated with an apparatus unit at a particular substation is operated, the first train of impulses operates the registers B simultaneously at all substations, but after the first train has been completed, only the selected substation remains in the line circuit to receive the subsequent impulses for selecting the unit. The operated key energizes one or other of an associated pair of relays such as 183, 184, 144, 145 or 271, 272 which energizes a relay 149 and locks up in series with an associated relay 156, 157, or 158, each of which is common to a group of keys individual to a substation. The operation of the relay 149 prevents the initiation of a control operation by a subsequently operated key until after the completion of the signalling operation and the operated relay 156, 157, or 158, prevents confusion of signals if two keys in different substation panels are operated simultaneously. The operated relay 156, 157 or 158 also operates a " start " relay 160 which connects battery to the line 139 and earths the lead 164 to complete a circuit through the back contacts of a group C of sequence control relays 113 - - 118, operated contact of the key relay, e.g. the relay 184 to a corresponding relay. e.g: 110 in the relay register A. The marked relay in the register operates a relay 169, which in turn energizes a relay 170 to earth the line 138 and thereby connect the relays 175 and 334 at each substation in series over the line wires 138, 139. The relay 170 also operates the sequence control relay 113. The line relay 334 at each substation operates register relay 301 which energizes a relay 344 to open the line circuit and operate a slow-release relay 349 which energizes the sequence control relay 307 in the group D. The relay 175 at the control station operates a relay 109 over the operated contacts of the relay 110 and when the line current is opened the relay 108 is energized over the operated contacts of relay 109. The relay 344 at each substation also connects a relay 347 across the lines 139, 140 and when the relay 175 is de-energized, the relay 347 is operated in series with a relay 181 at the control station. The relay 347 de-energizes the relay 334, which has been locked energized when the line was opened, and the register relay 302 is energized through the normal contacts of relay 334 and operated contacts of the relav 301. The relay 302 opens the circuit of the relay 344 and restores the circuit over the lines 138, 139 and another impulse is transmitted to energize the relays 334, 175 and produce similar operations of the relay registers. Impulsing proceeds until the last relay 107 in the register at the control station is operated. This relay energizes a " stop '' relav 182 which opens the line 138 and prevents further impulsing. During impulsing relay 349 remains operated, but when the impulses cease, the contact 350 falls back and operates the sequence control relay 308 which operates the switching relay 361. At the selected substation a circuit is then closed from a marking wire 362, 363 or 364 over the contacts of relav 361 to a relay 346 which energizes a relay 370 to open the line circuit momentarily and de-energizes the switching relay 361. At all other stations the circuit is extended from the corresponding marking wire 362, 363 or 364 to relays such as 367 which opens the line circuit at contacts 338 and connects the relays 347 at all unwanted stations across the lines 139, 140. These relays open the holding circuits of relays 367 at all unwanted substations at the completion of the unit selecting operation. At the control station the operation of the " stop " relay 182 causes the, energization of the relay 170 which is maintained energized during impulsing and thereby operates the next sequence control relay 114 and restores to normal the operated relays in the register. Restoration of the relay register de-energizes the relay 182 which upon retraction again operates a relay in the register A corresponding to the operated control key over the operated contacts of the sequence control relay 114 and the appropriate key relay. The energized relay in the register again operates the relay 170 which energizes the next sequence control relay 115 and completes the line circuit over the relays 334, 175 to initiate the second train of impulses. Selection of apparatus unit. The circuits for opening or closing the unit corresponding to the operated key are then prepared by two trains, each having a characteristic number of impulses. Impulses in the first of these trains are transmitted until the relay 170 energizes the " stop " relay 182, when the next sequence relay 116 is operated and a relay in the register is again marked in a manner characteristic of the operated key. This train of impulses operates at the selected substation the register B up to a point corresponding to the number of impulses and energizes the next sequence relay 309. At the end of the train, the relay 310 is energized due to the relapse of relay 349 to operate a, switching relav 373. This relay together with the last operated relay in the register B establishes a circuit for a relav in the group 325, 326 - - - which operates the relay 370 to open the line circuit, releases the operated register relays and de-energizes the relay 373 to open the circuit of the relay 370 and again complete the line circuit. The system is now readv for the transmission of the third train of impulses which operates the register and sequence relay chains in a similar manner until when the train ceases the final sequence relay 312 at the substation operates a switching relay 378 which together with the last operated relay in the register B energizes the appropriate relay in the group 327 - - 329 in series with a relay 377. A circuit is now closed over the contacts of the operated switching relays to a relay for the initiation of a checking signal of the selection. If, for example, it is desired to close the circuit breaker 331, the second and third impulse trains consist of one and two impulses respectively which cause the operation of the switching relays 325, 328 and the energization over the contacs thereof of a relay 384, which starts the transmission to the control station of the supervisory check. Transmission of signal for checking selection. The operated relay, such as 384, associated with the selected circuit breaker, operates a " start " relay 392 and the corresponding relay in the register E. The register relay causes the operation of a relay 406 which connects a relay 407 across the lines 141, 143 to test the lines and preclude the signal transmission if signals are being sent from another substation. If the lines are clear the relay 406 also operates relay 400, which connects the impulsing relay 416 across the lines 141, 142 and disconnects the " test " relay 407. The relay 416 is energized in series with a relay 199 at the control station. Impulses are then sent until the last relay 313 of the register E operates the " stop " relay 418 to prevent further impulsing and the register F at t