US3927851A - Alternating current track circuit apparatus - Google Patents

Alternating current track circuit apparatus Download PDF

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Publication number
US3927851A
US3927851A US540358A US54035875A US3927851A US 3927851 A US3927851 A US 3927851A US 540358 A US540358 A US 540358A US 54035875 A US54035875 A US 54035875A US 3927851 A US3927851 A US 3927851A
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US
United States
Prior art keywords
track
winding
alternating current
relay
series
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 - Lifetime
Application number
US540358A
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English (en)
Inventor
Clinton S Wilcox
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SASIB SpA
Original Assignee
General Signal Corp
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Filing date
Publication date
Application filed by General Signal Corp filed Critical General Signal Corp
Priority to US540358A priority Critical patent/US3927851A/en
Priority to CA241,463A priority patent/CA1043435A/en
Publication of US3927851A publication Critical patent/US3927851A/en
Application granted granted Critical
Priority to NL7600200.A priority patent/NL161101C/xx
Priority to GB821/76A priority patent/GB1529623A/en
Priority to IT12410/76A priority patent/IT1067244B/it
Priority to AU10222/76A priority patent/AU493267B2/en
Priority to ZA00760143A priority patent/ZA76143B/xx
Assigned to SASIB S.P.A. reassignment SASIB S.P.A. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: GENERAL SIGNAL CORPORATION, A CORP. OF NEW YORK
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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

Definitions

  • ABSTRACT Alternating current track circuit apparatus is provided for obtaining optimum shunting sensitivity throughout a stretch of track divided by insulated joints into adjoining double rail track circuits and having impedance bonds at respective transmitting and receiving ends.
  • An alternating current track feed is connected to the track rails at the transmitting end of each of the track circuits through a circuit tuned to resonance by a capacitor connected in series with a winding of the impedance bond at that end for energization of the associated track circuit from a source of alternating current.
  • An alternating current receiver is provided for connection to the track rails at the receiving end of each of the track circuits through a circuit tuned to resonance by a capacitor in series with a winding of another of the impedance bonds and a track winding of a receiving relay for sensing the presence of a vehicle in the associated track section.
  • the receiver comprises a local source of energy derived from the same source as the transmitting apparatus and connected to a local winding of the relay in series with a variable capacitor for adjusting of the phase difference between energization of the track and local windings for providing optimum sensitivity of the relay.
  • FIG. 1 A first figure.
  • TRACK CIRCUITS TR-IooC PHASE SHIFT OF FIG.I TRACK CIRCUIT FOR I,ooo-e,oo0 FT. TRACK CIRCUITS SHUNT RES.
  • the present invention is particularly useful in the use of alternating current track circuits for electrified railroads having DC power propulsion.
  • a system of this character is disclosed in the Estwick U.S. Pat. No. 1,822,572, issued Sept. 8, 1931, andassigned to the same assignee (by change of name) as the present invention.
  • This patent is incorporated by reference in the present application.
  • This patent discloses in FIG. 1 a conventional alternating current track circuit for frequencies of -60 HZ using a track and local phase detecting relay for sensing occupancy of the associated track section.
  • the track feed energy and the energy for the local winding are obtained from the same source, and the track winding current lags the input voltage in accordance with inductive reactance of the track rails and of an adjustable reactance in series with the track rails at the feed end of the track circuit. It is the adjusted phase difference between the currents in the track and local windings that makes the track relay, which can be of a vane type, operable. Optimum operating conditionsare obtained when there is a 90 difference in the phase relationship of the track and local windings of the track relay.
  • An object of the present invention is to provide an alternating current double rail track circuit which substantially obviates one or more of the limitations and disadvantages of the described prior arrangements.
  • Another object of the present invention is to provide an alternating current track circuit having improved shunting sensitivity for long track circuits.
  • Alternating current track circuit apparatus for a stretch of railway track divided by insulated joints into adjoining double rail track circuits and having impedance bonds at respective transmitting and receiving ends of the track circuits permitting power propulsion direct current to bypass the joints.
  • An alternating current track feed is connected across the track rails at the transmitting end of each of the track circuits through a circuit tuned to resonance by a variable capacitor connected in series with a winding of the impedance bond at that end of the track section for energization of the associated track circuit from a source of alternating current.
  • An alternating current receiver is provided for the receiving end of each of the track circuits for connection across the track rails through a circuit tuned to resonance by a variable capacitor in series with a winding of another of the impedance bonds and a track winding of a receiving relay for sensing the presence of a vehicle in the associated track section.
  • the receiver comprises a local source of energy derived from the same source as the track feed and connected to a local winding of the relay in series with a variable capacitor for adjustment of the phase difference between energization of the track and local windings for providing optimum sensitivity of the relay.
  • FIG. 1 illustrates schematically a typical alternating current double rail track circuit according to a preferred embodiment of the present invention
  • FIG. 2 illustrates by vector diagrams typical prior art phase displacements of currents in a track winding as compared to applied voltage for different lengths of track circuits;
  • FIG. 3 illustrates by vector diagram typical phase displacements of current in a track winding as compared to applied voltage for different lengths of track circuits according to the preferred embodiment of the present invention as illustrated in FIG. I;
  • FIG. 4 illustrates the affect of variable capacitance in series with the local phase relay winding when the transmitting and receiving ends of the preferred embodiment of the present invention as illustrated in FIG. 1 are tuned to resonance.
  • alternating current track circuit apparatus is provided for a stretch of railway track 10 divided by insulated joints 11 into adjoining double rail track circuits l2, l3 and 14 respectively. These track circuits have impedance bonds at respective transmitting and receiving ends permitting power propulsion direct current to bypass the joints.
  • An alternating current track feed 16 is provided at the transmittingend of each of the track circuits and is connected to the track rails through a circuit tuned to resonance by a variable capacitor C1 connected in series with a winding 18 of bond 15 for energization of the associated track circuit from a source of alternating current 19.
  • An alternating current receiver 20 is connected across the rails at the right-hand end of each of the track sections through a circuit tuned to resonance by a variable capacitor C2 in series with a winding 22 of another of the impedance bonds 15. Also included in series in the receiving circuit is a track winding 23 of a track relay TR.
  • the receiver 20 also comprises a local source of energy 24 derived from the source 19 and connected to a local winding 25 of the relay TR in series with a variable capacitor C3.
  • the variable capacitor C3 is for adjustment of the phase difference between energization of the track and local windings of the track relay TR for providing optimum sensitivity of this relay.
  • a center tap of the primary winding 17 of each of the bonds 15 is connected to a corresponding center tap of the next adjoining bond 15 so that the DC. propulsion return bypasses the insulated joints I1.
  • FIG. 2 illustrates the phase shift of the track phase of a track relay TR relative to the supply voltage for different lengths of track circuits, assuming that only the relay end of the track circuit is tuned to resonance. It will be readily understood from this diagram that there is considerable difficulty in providing proper control for A.C. track circuits of varying length, particularly where long and short track sections are adjoining, and still provide broken down joint protection.
  • the capacitor C3 in series with the local winding 25 of relay TR is adjusted, after first tuning both ends of the track circuit to resonance. This adjustment is to a value providing close to 90 phase displacement between the track and local windings of the relay and to obtain a shunting resistance within the track circuit requirement calling for the track relay to be responsive to at least a 0.3 ohm resistance rail shunt.
  • shunt resistance and local-track phase difference curves 26 and 27 are obtained respespectively.
  • the optimum adjustment of the capacitor C3 is to a value corresponding to the point 26a of curve 26 corresponding to a 0.31 ohm shunting resistance. This adjustment obtains a phase difference between the track and local windings 23 and 25 corresponding to point 27a on curve 27.
  • the curves 26 and 27 are for a 6,000 foot 75HZ track circuit having a ballast resistance of ohms per thousand feet, and having the feed and relay ends of the track circuit tuned to resonance wherein capacitor C1 is adjusted to 2.24 mfd and capacitor C2 is adjusted to 2.3 mfd.
  • Shunting resistance 4 at point 26a of curve 26 is 0.31 ohms
  • the variable capacitor C3 is adjusted to 2.3 mfd
  • the phase difference between the local and track phases as represented by the point 27a is 90.
  • the track circuit thus provided according to the preferred embodiment of FIG. 1 can be adjusted for obtaining high track voltage and good shunting sensi tivity, and the local phase of the relay TR can be adjusted independently for the required operating characteristics, such adjustments all resulting in being able to provide full broken down joint protection for different lengths of adjoining track circuits.
  • the frequency of HZ has been chosen only for example and that frequencies from ZSHZ to IOOHZ could be used.
  • Alternating current track circuit apparatus for a stretch of railway track divided by insulated joints into adjoining double rail track circuits and having impedance bonds at respective transmitting and receiving ends permitting power propulsion direct current to bypass the joints, wherein the improvement comprises:
  • an alternating current track feed for connection across the track rails at the transmitting end of each of the track circuits through a circuit tuned to resonance by a capacitor connected in series with a winding of the impedance bond at that end for energization of the associated track circuit from a source of alternating current
  • an alternating current receiver for connection across the track rails at the receiving end of each of the track circuits through a circuit tuned to resonance by a capacitor in series with a winding of another of the impedance bonds and a track winding of a receiving relay for sensing the presence of a vehicle in the associated track section
  • the receiver comprising a local source of energy derived from said source and connected to a local winding of the relay in series with a variable capacitor for adjustment of the phase difference between energization of the track and local windings for providing optimum sensitivity of the relay,
  • Alternating current track circuit apparatus wherein the impedance bond for the receiver end of each of the track circuits has a primary winding connected across the track rails and has a center tap connected to a return conductor for propulsion current, the primary winding being inductively coupled to the bond winding in series with the track winding of a receiving relay.

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  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Mechanical Engineering (AREA)
  • Train Traffic Observation, Control, And Security (AREA)
US540358A 1975-01-13 1975-01-13 Alternating current track circuit apparatus Expired - Lifetime US3927851A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US540358A US3927851A (en) 1975-01-13 1975-01-13 Alternating current track circuit apparatus
CA241,463A CA1043435A (en) 1975-01-13 1975-12-10 Occupancy detecting a.c. track circuit apparatus
NL7600200.A NL161101C (nl) 1975-01-13 1976-01-09 Wisselstroom-spoorstroomloop voor spoorbaansecties.
GB821/76A GB1529623A (en) 1975-01-13 1976-01-09 Alternating current track circuit apparatus
IT12410/76A IT1067244B (it) 1975-01-13 1976-01-12 Circuito elettrico in corrente alternata per binario ferroviario particolarmente per ferrovie elettrificate con propulsione in c.c.
AU10222/76A AU493267B2 (en) 1975-01-13 1976-01-12 Alternating current track circuit apparatus
ZA00760143A ZA76143B (en) 1975-01-13 1976-01-12 Alternating current track circuit apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US540358A US3927851A (en) 1975-01-13 1975-01-13 Alternating current track circuit apparatus

Publications (1)

Publication Number Publication Date
US3927851A true US3927851A (en) 1975-12-23

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ID=24155108

Family Applications (1)

Application Number Title Priority Date Filing Date
US540358A Expired - Lifetime US3927851A (en) 1975-01-13 1975-01-13 Alternating current track circuit apparatus

Country Status (6)

Country Link
US (1) US3927851A (xx)
CA (1) CA1043435A (xx)
GB (1) GB1529623A (xx)
IT (1) IT1067244B (xx)
NL (1) NL161101C (xx)
ZA (1) ZA76143B (xx)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4886226A (en) * 1988-06-23 1989-12-12 General Signal Corporation Broken rail and/or broken rail joint bar detection
US5094413A (en) * 1988-10-26 1992-03-10 Bailey Esacontrol S.P.A. Device for the protection of track relays from electrical disturbances
US5181679A (en) * 1991-08-22 1993-01-26 General Railway Signal Corporation Railway train speed restriction apparatus
US5219426A (en) * 1992-02-25 1993-06-15 Union Switch & Signal Inc. Single-element coded alternating current railway track circuit having double-element, phase-selective capability
GB2440765A (en) * 2006-08-10 2008-02-13 Hitachi Ltd Track circuit with phase difference adjustment
US20100163686A1 (en) * 2008-12-26 2010-07-01 Mag-Con Engineering Double impedance bond
WO2012130667A1 (de) * 2011-03-31 2012-10-04 Siemens Aktiengesellschaft Vorrichtung zur detektion des belegt- oder freizustandes eines gleisabschnitts sowie verfahren zum betreiben einer solchen vorrichtung
CN103158739A (zh) * 2013-03-18 2013-06-19 彭岚 一种动态处理铁路轨道分路不良的方法及装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8402359D0 (en) * 1984-01-30 1984-02-29 Westinghouse Brake & Signal Track circuit

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2605390A (en) * 1948-10-13 1952-07-29 Gen Railway Signal Co Coded track circuit signaling systems
US2854567A (en) * 1954-04-23 1958-09-30 Westinghouse Air Brake Co Railway traffic controlling apparatus
US2986628A (en) * 1956-06-01 1961-05-30 Forges Ateliers Const Electr Track circuits

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2605390A (en) * 1948-10-13 1952-07-29 Gen Railway Signal Co Coded track circuit signaling systems
US2854567A (en) * 1954-04-23 1958-09-30 Westinghouse Air Brake Co Railway traffic controlling apparatus
US2986628A (en) * 1956-06-01 1961-05-30 Forges Ateliers Const Electr Track circuits

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4886226A (en) * 1988-06-23 1989-12-12 General Signal Corporation Broken rail and/or broken rail joint bar detection
US5094413A (en) * 1988-10-26 1992-03-10 Bailey Esacontrol S.P.A. Device for the protection of track relays from electrical disturbances
US5181679A (en) * 1991-08-22 1993-01-26 General Railway Signal Corporation Railway train speed restriction apparatus
US5219426A (en) * 1992-02-25 1993-06-15 Union Switch & Signal Inc. Single-element coded alternating current railway track circuit having double-element, phase-selective capability
CN101121413B (zh) * 2006-08-10 2011-04-06 株式会社日立制作所 轨道电路
GB2440765A (en) * 2006-08-10 2008-02-13 Hitachi Ltd Track circuit with phase difference adjustment
GB2440765B (en) * 2006-08-10 2008-06-25 Hitachi Ltd Track circuit
US20100163686A1 (en) * 2008-12-26 2010-07-01 Mag-Con Engineering Double impedance bond
US8333350B2 (en) * 2008-12-26 2012-12-18 Mag-Con Engineering Double impedance bond
WO2012130667A1 (de) * 2011-03-31 2012-10-04 Siemens Aktiengesellschaft Vorrichtung zur detektion des belegt- oder freizustandes eines gleisabschnitts sowie verfahren zum betreiben einer solchen vorrichtung
US20140014783A1 (en) * 2011-03-31 2014-01-16 Siemens Aktiengesellschaft Device for detecting the occupied or available status of a track segment and method for operating such a device
US9139211B2 (en) * 2011-03-31 2015-09-22 Siemens Aktiengesellschaft Device for detecting the occupied or available status of a track segment and method for operating such a device
AU2012234517B2 (en) * 2011-03-31 2016-12-08 Siemens Mobility GmbH Device for detecting the occupied or available status of a track segment and method for operating such a device
CN103158739A (zh) * 2013-03-18 2013-06-19 彭岚 一种动态处理铁路轨道分路不良的方法及装置
CN103158739B (zh) * 2013-03-18 2015-05-13 彭岚 一种动态处理铁路轨道分路不良的方法及装置

Also Published As

Publication number Publication date
IT1067244B (it) 1985-03-16
NL161101B (nl) 1979-08-15
ZA76143B (en) 1976-12-29
AU1022276A (en) 1977-07-21
CA1043435A (en) 1978-11-28
GB1529623A (en) 1978-10-25
NL7600200A (nl) 1976-07-15
NL161101C (nl) 1980-01-15

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Date Code Title Description
AS Assignment

Owner name: SASIB S.P.A., VIA DI CORTICELLA 87/89, 40128 BOLOG

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GENERAL SIGNAL CORPORATION, A CORP. OF NEW YORK;REEL/FRAME:005646/0241

Effective date: 19910311