CHOPPERS AFFECT OPERATION OF AF TRACK CIRCUITS

Interference has been observed on US metros between the latest chopper-controlled trains and coded track circuits used for train detection as well as cab signals and ATO. The most dominant interference mechanism is inductive coupling between equipment carried on the car and the loop formed by the rails and axles under the car. Currents induced in this loop can result in transient "track clear" indications as a powered car passes over the impedance bond separating adjacent track circuits. A joint government-industry working group is developing ways of quantifying and controlling the problem.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03735346
• Corporate Authors:

  IPC Transport Press, Limited

  Dorset House, Stamford Street
  London SE1 9LU,   England 
• Authors:
  • Frasco, L A
• Publication Date: 1980-4

Media Info

• Pagination: p. 291-294
• Serial:
  • Railway Gazette International
  • Volume: 136
  • Issue Number: 4
  • Publisher: DVV Media Group
  • ISSN: 0373-5346
  • Serial URL: http://www.railwaygazette.com/about-us.html

Subject/Index Terms

• TRT Terms: Automatic train operation; Chopper circuits; Inductive interference; Interference; Rapid transit cars; Track circuits
• Old TRIS Terms: Choppers; Coded track circuits; Impedance bonds
• Subject Areas: Public Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00316565
• Record Type: Publication
• Source Agency: British Railways
• Files: TRIS
• Created Date: Sep 16 1981 12:00AM