Patent GB-280254-A (GB)
Title: Improvements relating to electrical remote control and signalling systems
IPC: H02J13/00
Filed: 1926-06-08
Abstract: 280,254. Siemens Bros. & Co., Ltd., and Humphries, H. E. June 8, 1926. Selective distant control systems; tell-tale apparatus.-In a remote control and supervisory signalling system for a plurality of substations connected across common line wires, the initiation of a signal at a substation prevents signal transmission from preceding stations by reason of circuit changes brought about at the preceding stations directly due to the passage of impulses from the signalling station. The line circuit to subsequent stations is opened to prevent interference with the signalling substation. Figs. 1 - - 4 show the apparatus at the control station and Figs. 5 - - 8 show the equipment located at each substation. An apparatus unit e.g. a circuit breaker at a substation may be operated by an appropriate key e.g. ONS which when operated causes finder switches ASF, EOF to hunt for marked contacts. Consequent upon this operation, impulse trains characteristic of the substations and apparatus unit are transmitted over the lines A, B to operate switches BSM at all substations and switch BOM at the selected station respectively and thereby select and operate the appropriate unit control relay FA. When a unit changes its position three trains of impulses are transmitted over the line wires A<1>, B<1> under the control of switches CCR, CFR, COC. The first train constitutes a special train to safeguard against signal mutilation should two or more stations commence signalling simultaneously. The second and third trains are characteristic of the station and operated unit and cause the operation of signal lamps at the control station over contacts selected by the switches DSM, BOM. Special keys are provided for associating meters at the control office with apparatus units and regulating the units in accordance with the metered indications. Additional keys are also provided for facilitating routine and fault tests, battery charging &c. Apparatus at several substations may be operated simultaneously and the line wires may be utilized for telephonic communication. Selecting substation and apparatus unit. Each unit, for example a circuit-breaker, at a substation has a control key OZS at the control station, which, when operated together with a " start " key SK causes the operation of a relay EZ individual to the key to mark contacts in the banks E, C of the substation and apparatus unit finder switches ASF, EOF respectively. The relay EZ comprises four windings a - - d, the windings a, b being associated with the key and the windings c, d being adapted to restore the relay to normal subsequent to the transmission of the signal code. The relay is energized by short-circuiting one or other of the windings a, b. The start key SK may be replaced by a switch which can only be operated by a key. A relay AP is also energized to start the motor MI of the interrupters Nos. 1, 2 and 3. The first impulse of interrupter No. 1 operates the relays AX, AY in turn, the latter switching interrupter No. 3, on to the stepping magnet ASF, provided the switch ART is. at normal. The switch ASF is stepped up to its marked contact to energize relay AE and thereby transfers the impulsing circuit of interrupter No. 3 to the magnet EOF of the unit finder switch. This switch moves up to its marked contact and a relay AN is energized to open the driving circuit. The relay AN causes the switches AOC, ART to move one step forward. Normally a high resistance relay AA, Fig. 4, is in series with the substation line relays BL, Fig. 6, over the line wire B, wipers ART(A), AOC(A). When the switch ART is operated, the relay AA is cut out of the line circuit and a heavy current flows over the line circuit, a series relay AC being thereby energized. This current is maintained for a predetermined time by the action of the switch ACR to ensure that the substation line relays are fully fluxed and operated. If the continuity of the line circuit is broken relay AC remains de-energized and prevents operation of the switch ACR and in consequence the initiation of impulse transmission. The switch ACR is stepped up to the seventh contact (marking wire a) under the control of interrupter No. 1, to operate the switch AOC, a further step and thereby switch interrupter No. 2, in the line circuit for transmitting the first impulse train, viz., the substation selecting train. The switch AOC also brings the switch ACR under the control of interrupter No. 1, and stepping takes place until the switch AOC is moved a further step consequent upon wiper B of the switch ACR co-operating with a contact connected to the marked contact in bank ASF(A). During this period the first impulse train is transmitted over the line wires, but finally movement of the switch AOC short-circuits the interrupter No. 2 and line impulsing ceases. The switch AOC also causes the switch ACR to drive to normal and then move up to contact marked by wire a to produce an inter train pause. Meanwhile the switch AOC moves to again connect interrupter No. 2 in the line circuit. The character of the second train for selecting the apparatus unit is determined in a manner similar to that described above, by the switch ACR which is impulsed by interrupter No. 1, until a circuit is closed over the switches ACR, ASF, EOF for operating the switch AOC a further step to terminate the second impulse train and permit current to flow steadily in the line circuit. The switch AOC then operates a relay AH which illuminates a coding out lamp COL and causes the switch ACR to drive to normal and then up to the contact marked by wire b. This operation constitutes a post impulsing pause and causes the switch AOC to take further steps and thereby cause switch ART to move a further step to open the line circuit, and nullify the coding out signal Normally the weak line current does not operate the line relays BL at the substations but when the heavy current is switched on to the line at the control point the relays BL at all stations are operated in series over the lines A, B. The first train of impulses operates the relays BL and in consequence the switches BSM at all substations. The inter-train pause causes the operation of a relay BS which transfers the impulsing circuit at the substations to the wipers BSM(A) which are set in positions characteristic of the first train. The stepping magnet BOM at each substation is connected to a different contact in the banks associated with wipers BSM(A) so that the second train operates apparatus at one station only. The switch BOM is impulsed by the second train to select the relay, such as FA, which corresponds to the operated control key. The post-impulsing pause, which is created by the action of the switch ACR and permits the steady application of current to the line ensures complete operation of the selected relay FA. The relay FA controls the apparatus unit. In the arrangement shown in Figs. 5 and 6, provision is made for the selection of units, the number of which is greater than the number of contacts in one bank of the switch BOM. Two contacts in the bank BSM(A) are strapped to terminals BSS1, BSS2 and the switch BSM may be set into one or other of these contacts in order to effect a selection of one or other banks of contacts BOM(A), BOM(B). Release after selection and operation. Movement of the switch ART on to its third contact at the end of the impulse trains causes the energization of relay AJ which energizes over a circuit including wipers EOF(B), ASF(C) the release winding c of the relay EZ. De-energization of the relay EZ releases the relays AB, AN and the switches ACR, AOC are restored in turn to normal. When switch AOC reaches normal, switch ART moves a further step to release relay AJ. The switch ART is then driven to normal under the control of interrupter No. 1, and the high resistance relay AA is again switched into the line circuit. The holding circuit of relay AP is also opened and in consequence the interrupter motor is stopped. The long break in the line circuit at the end of impulsing provides sufficient time for switches BSM, BOM to step to normal. The apparatus at the control and substations may be released during impulsing by changing the position of the key OZS and thus releasing the relay EZ. A lamp associated with the operated key is illuminated by the relay EZ. Supervisory signalling. Normally relays FZ associated with each apparatus unit and relays CL at each substation are energized. The relays CL are fed from the control station in series over the lines A<1>, B<1>. When an apparatus unit changes the position of an associated contact pc the relay FZ is de-energized and a contact in the bank CFR(B) is marked. Release of relay FZ causes operation of relay CP which starts the interrupter motor M1 and switches the interrupter No. 2 in series with a relay CX. Relay CX prepares relay CY which operates upon first opening of interrupter No. 2. The relay CY brings the stepping magnet CFR under the control of interrupter No. 3 and the switch CFR is advanced up to the marked contact to close a circuit for one or other of the relays CA, CB. The relay CA is appropriated to units selected by the wiper BOM(A) while the relay CB is common to the additional units associated with wiper BOM(B). The relay CA or CB switches the circuit of interrupter No. 2 over to magnet OCR which initially moves its switch a number of steps in order to facilitate the attainment of normal interrupter speed in the event that the switch CPR already occupies its marked position at the commencement of signalling. The next impulse produced by interrupter No. 2 and directed over the wiper OCR(B) energizes relays CNA, CNB, which lock. The relay CNB switches magnet COC into the circuit of interrupter No. 2 and interrupter No. 1 into the line circuit. Interrupter No. 1, produces the first line break and then due to phase displacement, interrupter No. 2 opens and switch COC mo