GB1504516A - Interogator/transponder system - Google Patents

Interogator/transponder system

Info

Publication number
GB1504516A
GB1504516A GB1462674A GB1462674A GB1504516A GB 1504516 A GB1504516 A GB 1504516A GB 1462674 A GB1462674 A GB 1462674A GB 1462674 A GB1462674 A GB 1462674A GB 1504516 A GB1504516 A GB 1504516A
Authority
GB
United Kingdom
Prior art keywords
interrogator
signal
vehicle
returned
phase
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
Application number
GB1462674A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Plessey Co Ltd
Original Assignee
Plessey Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Plessey Co Ltd filed Critical Plessey Co Ltd
Priority to GB1462674A priority Critical patent/GB1504516A/en
Publication of GB1504516A publication Critical patent/GB1504516A/en
Expired legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B61—RAILWAYS
    • B61L—GUIDING RAILWAY TRAFFIC; ENSURING THE SAFETY OF RAILWAY TRAFFIC
    • B61L25/00—Recording or indicating positions or identities of vehicles or trains or setting of track apparatus
    • B61L25/02—Indicating or recording positions or identities of vehicles or trains
    • B61L25/04—Indicating or recording train identities
    • B61L25/043—Indicating or recording train identities using inductive tags
    • G—PHYSICS
    • G08—SIGNALLING
    • G08G—TRAFFIC CONTROL SYSTEMS
    • G08G1/00—Traffic control systems for road vehicles
    • G08G1/01—Detecting movement of traffic to be counted or controlled
    • G08G1/017—Detecting movement of traffic to be counted or controlled identifying vehicles

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

1504516 Interrogator-responder systems PLESSEY CO Ltd 24 March 1975 [2 April 1974] 14626/74 Heading H4L In an interrogator-responder system for use in vehicle detection, the direction of travel of the vehicle is assessed at the interrogator, by comparing the phase of the signal returned from the vehicle responder (this signal comprising a data signal having a frequency related to the interrogator clock frequency) with that of a reference signal derived from the interrogator clock frequency radiated to the vehicle. When the returned signal is at half the clock frequency, for one direction of travel the phase of the returned signal will either be the same or different by # from the reference, while in the other direction it will be #/2 leading or lagging. It is desirable to arrange the transponder receiver end transmitter loops in upright positions in the vehicle perpendicular to the road and also at right angles to the direction of movement. If the relationship between the returned and clock frequencies is some factor other than half, then some other phase relationship will apply.
GB1462674A 1975-03-24 1975-03-24 Interogator/transponder system Expired GB1504516A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1462674A GB1504516A (en) 1975-03-24 1975-03-24 Interogator/transponder system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1462674A GB1504516A (en) 1975-03-24 1975-03-24 Interogator/transponder system

Publications (1)

Publication Number Publication Date
GB1504516A true GB1504516A (en) 1978-03-22

Family

ID=10044667

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1462674A Expired GB1504516A (en) 1975-03-24 1975-03-24 Interogator/transponder system

Country Status (1)

Country Link
GB (1) GB1504516A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4674618A (en) * 1983-12-06 1987-06-23 Mars Incorporated Tokens and token handling devices
EP0618557A1 (en) * 1993-03-31 1994-10-05 PREH-WERKE GmbH & Co. KG Information transmitting device for road traffic

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4674618A (en) * 1983-12-06 1987-06-23 Mars Incorporated Tokens and token handling devices
US4926996A (en) * 1983-12-06 1990-05-22 Mars Incorporated Two way communication token interrogation apparatus
EP0618557A1 (en) * 1993-03-31 1994-10-05 PREH-WERKE GmbH & Co. KG Information transmitting device for road traffic

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Legal Events

Date Code Title Description
PS Patent sealed
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PE20 Patent expired after termination of 20 years

Effective date: 19950323