GB826553A - Improvements relating to alternating current track circuits for railway signalling systems - Google Patents
Improvements relating to alternating current track circuits for railway signalling systemsInfo
- Publication number
- GB826553A GB826553A GB3146455A GB3146455A GB826553A GB 826553 A GB826553 A GB 826553A GB 3146455 A GB3146455 A GB 3146455A GB 3146455 A GB3146455 A GB 3146455A GB 826553 A GB826553 A GB 826553A
- Authority
- GB
- United Kingdom
- Prior art keywords
- relay
- track
- current
- transformer
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000011664 signaling Effects 0.000 title abstract 6
- 238000004804 winding Methods 0.000 abstract 4
- 239000011162 core material Substances 0.000 abstract 2
- 230000005415 magnetization Effects 0.000 abstract 2
- 229920006395 saturated elastomer Polymers 0.000 abstract 2
- 238000009413 insulation Methods 0.000 abstract 1
- 239000002184 metal Substances 0.000 abstract 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B61—RAILWAYS
- B61L—GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
- B61L23/00—Control, warning or like safety means along the route or between vehicles or trains
- B61L23/08—Control, warning or like safety means along the route or between vehicles or trains for controlling traffic in one direction only
- B61L23/14—Control, warning or like safety means along the route or between vehicles or trains for controlling traffic in one direction only automatically operated
- B61L23/16—Track circuits specially adapted for section blocking
- B61L23/166—Track circuits specially adapted for section blocking using alternating current
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B61—RAILWAYS
- B61L—GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
- B61L1/00—Devices along the route controlled by interaction with the vehicle or train
- B61L1/18—Railway track circuits
- B61L1/181—Details
- B61L1/187—Use of alternating current
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Automation & Control Theory (AREA)
- Train Traffic Observation, Control, And Security (AREA)
Abstract
826,553. Railway signalling track circuits. WESTINGHOUSE BRAKE & SIGNAL CO. Ltd., DUCKITT, H., and TILLOTSON, P. Oct. 26, 1956 [Nov. 3, 1955], No. 31464/55. Class 105. In a railway A.C. track signalling system in which one or both rails may be used as a return for A.C. traction current and in which filter circuits are used to pass the A.C. signalling current of frequency different to that of the traction current through a rectifying device to a D.C. relay, in order to avoid at the relay end of the section, due e.g. to a break in a rail or impedance bond, the possibility of current of traction power frequency through the relay of " critical " strength such as to hold the relay when a vehicle enters the section, a saturable transformer is connected between the filter circuit and the track rails at the relay end and is designed to become saturated when the builtup voltage of traction power frequency attains a predetermined value below the " critical " value. The saturable core may be of " Mumetal " (Registered Trade Mark) or of " H.C.R." metal the magnetization curve of which has a sharp cut-off. In cases where one continuous track rail is used, a voltage build-up of traction power frequency may occur due e.g. to the presence of a train in an adjacent section, the saturable transformer may become saturated and release the track relay without a vehicle in the section and to avoid this a second filter to pass the signalling frequency is inserted between the transformer and the track rails (Fig. 3, not shown). To provide protection against failure of rail-joint insulation resulting in false energization of the relay, adjacent track circuits may be operated with A.C. signal currents of different frequencies, the filter network of a circuit responding only to the signal frequency for that circuit or alternatively by employing an A.C. circuit adjacent a D.C. circuit or in the case of coded A.C. track circuits using double rail traction power return sections with impedance bonds, by using different code or modulation frequencies for adjacent track circuits. The filter circuits may have a single stage (Fig. 1, not shown) or a plurality of seriescoupled stages (Fig. 2, not shown). When coded signalling current is used, the relay constitutes a code-following relay controlling a decoding apparatus which in turn controls a track signal (Fig. 4, not shown). As shown in Fig. 5 the relay equipment is made phase-sensitive. The saturable transformer 8 feeds, through a filter 11 tuned to the signal frequency, a centretapped transformer 28 preferably of small magnetizing current, the secondary winding of which feeds two full-wave rectifiers 30, 31 of a modulator type circuit, the outputs of the rectifiers being fed respectively to the identical opposing windings of a code following relay 32 together with an A.C. voltage from a generator 35 of signal current frequency in phase with that at the feed end of the track circuit. This generator 35 is connected between the centre tap of the secondary winding 29 of the transformer 28 and a common connection 34 of the two rectifiers 30, 31, so as to be in phase with the input of one rectifier and in phase opposition to the input of the other rectifier. The relay 32 is of the direct-current polar kind it only pulls up when the lower winding has the stronger energization to control the decoding apparatus network 26 the selective output of which controls the signal 36. The track feed apparatus 24 may also be protected against the traction current by feeding the track rails through a saturable transformer 6, the core material of which need not have such a sharp cut-off in its magnetization curve as that of the relay end transformer 8. Specification 823,045 is referred to.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3146455A GB826553A (en) | 1955-11-03 | 1955-11-03 | Improvements relating to alternating current track circuits for railway signalling systems |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3146455A GB826553A (en) | 1955-11-03 | 1955-11-03 | Improvements relating to alternating current track circuits for railway signalling systems |
Publications (1)
Publication Number | Publication Date |
---|---|
GB826553A true GB826553A (en) | 1960-01-13 |
Family
ID=10323474
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3146455A Expired GB826553A (en) | 1955-11-03 | 1955-11-03 | Improvements relating to alternating current track circuits for railway signalling systems |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB826553A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3287554A (en) * | 1963-11-01 | 1966-11-22 | Westinghouse Air Brake Co | Railway track circuit apparatus |
WO2011159326A1 (en) * | 2010-06-18 | 2011-12-22 | General Electric Company | Foreign track current suppression system and method |
CN106240602A (en) * | 2016-07-08 | 2016-12-21 | 浙江众合科技股份有限公司 | A kind of method detecting orbit occupancy |
CN112147486A (en) * | 2020-09-23 | 2020-12-29 | 中铁电气化局集团有限公司 | 25HZ phase-sensitive track circuit simulation tester and testing method |
-
1955
- 1955-11-03 GB GB3146455A patent/GB826553A/en not_active Expired
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3287554A (en) * | 1963-11-01 | 1966-11-22 | Westinghouse Air Brake Co | Railway track circuit apparatus |
WO2011159326A1 (en) * | 2010-06-18 | 2011-12-22 | General Electric Company | Foreign track current suppression system and method |
US8376286B2 (en) | 2010-06-18 | 2013-02-19 | General Electric Company | Foreign track current suppression system and method |
GB2494348A (en) * | 2010-06-18 | 2013-03-06 | Gen Electric | Foreign track current suppression system and method |
GB2494348B (en) * | 2010-06-18 | 2015-11-04 | Gen Electric | Foreign track current suppression system and method |
CN106240602A (en) * | 2016-07-08 | 2016-12-21 | 浙江众合科技股份有限公司 | A kind of method detecting orbit occupancy |
CN106240602B (en) * | 2016-07-08 | 2018-10-23 | 浙江众合科技股份有限公司 | A method of detection orbit occupancy |
CN112147486A (en) * | 2020-09-23 | 2020-12-29 | 中铁电气化局集团有限公司 | 25HZ phase-sensitive track circuit simulation tester and testing method |
CN112147486B (en) * | 2020-09-23 | 2024-06-11 | 中铁电气化局集团有限公司 | 25HZ phase-sensitive track circuit simulation tester and testing method |
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