
	Where results make sense

Topic: Track circuits

Related Topics

integrated circuit

printed circuit board

Suzuka Circuit

digital circuit

electrical circuit

Silverstone Circuit

short circuit

switching circuits

Closed circuit television

Series and parallel circuits

Circuit political division

circuit breaker

In the News (Thu 16 Feb 12)

EXECUTIVE POWER

Iran

ANALYSIS

Pakistan

Family compact

	Track circuits - Wikipedia, the free encyclopedia
		A track circuit is a simple electric device to detect the presence of trains on the track, which can be used to inform the signalmen, and to control the relevant signals.
		The track circuits on Cowan bank affected by sand on the rails were NOT indicated to any signalbox.
		The track circuit current may be modulated at different frequencies, which can be detected by equipment on the train to provide the driver with a signal indication inside the cab.
	en.wikipedia.org /wiki/Track_circuits (915 words)

	Track circuit - Wikipedia, the free encyclopedia
		A track circuit is an electrical circuit used to detect the presence of a train.
		The fail-safe design of a track circuit means that, should a fault such as power failure occur, the track circuit will show the track to be occupied, to prevent another train from being given movement authority onto the track.
		DC track circuits are made with DC track relays and supply, and insulating block joints on each track isolate each circuit from the next along the track.
	en.wikipedia.org /wiki/Track_circuit (428 words)

	DC TRACK CIRCUITING (Site not responding. Last check: 2007-10-13)
		The idea of the circuit is that when the track is clear, and the signal lever is set to the green position, the signal goes green.
		The bells and lights in a level crossing circuit are turned on by the track relays of the track section on the level crossing as well as the section approaching it.
		AC track circuits are used in the automatic sections of the mainline (the sections where there are no points and signals are not controlled by signalboxes, but operate automatically), where AC Multiplexing Signalling Systems are used.
	www.dvr.com.au /stinfo1.htm (2513 words)

	Broken rail detecting track circuits - Patent 4117529
		Another object of the invention is track circuit apparatus for detecting a broken rail within a track section in which lengths of the rails are electrically connected to form parallel circuit paths.
		A further object of the invention is circuit apparatus for a railroad track section, in which rail lengths are electrically connected in parallel, which uses current from the train detector track circuit to also detect broken rails.
		A still further object of the invention is a track circuit arrangement for assuredly detecting broken rails in a dual gage track section in which track turnouts exist.
	www.freepatentsonline.com /4117529.html (6703 words)

	Signals - Track Circuits, Warning Systems and Industrial Signalling (Site not responding. Last check: 2007-10-13)
		At the end of each length of track forming a single circuit the rails are joined with white insulating fishplates (he bolts are the standard rust coloured type).
		Track circuits were introduced in the British railways in the early part of the twentieth century but they only really became common in the later 1920’s.
		One odd use was on the LNER line into London in the late 1930’s where electric colour light signals were activated by an approaching train operating a track circuit, the theory being that as the light was not burning continually it would last longer, the idea did not catch on however.
	myweb.tiscali.co.uk /gansg/3-sigs/indusig.htm (3052 words)

	[No title] (Site not responding. Last check: 2007-10-13)
		These are circuits 210,211 and 212 in the first sub-stage 21 and circuits 220,221 and 222 in the second sub-stage 22.
		A number of track & hold circuits different from three is alternatively possible, which is also dependent on the number of inputs of the picture display panel 3.
		For a practical circuit, it is important for the uniformity of the channels that all FETs of the track & hold circuits 210...
	www.wipo.int /cgi-pct/guest/getbykey5?KEY=00/52669.000908&ELEMENT_SET=DECL (1942 words)

	Track circuits on the third rail network (Site not responding. Last check: 2007-10-13)
		Abutting track circuits are traditionally separated by insulated joints, and these would obstruct the flow of the DC traction current, so a bypass path has to be engineered at each interface between adjacent track circuits.
		The track circuit's AC supplies cannot follow, and are directed instead into cables which link to trackside equipment cupboards, where the track circuit feed and relays are housed.
		Through points, one rail is insulated for track circuit separation, and the returning traction current is confined to one rail for a short distance.
	www.semg.org.uk /proto/3rts.html (401 words)

	49 CFR PART 236 (Site not responding. Last check: 2007-10-13)
		When an electric lock releasing circuit is provided on the main track to permit a train or an engine to diverge from the main track without time delay, the circuit shall be of such length to permit occupancy of the circuit to be seen by a crew member stationed at the switch.
		The track circuit in the fouling section of a turnout, connected in multiple with the track circuit in the main track.
		A circuit controller which is part of the switch operating mechanism and operated by a rod connected to a switch, derail or movable point frog to indicate that the point is within a specified distance of the stock rail.
	www.washingtonwatchdog.org /documents/cfr/title49/part236.html (10577 words)

	[No title]
		J[R] In some circuits, a J relay is energized in conjunction with the corresponding H relay to clear a signal to the Proceed aspect.
		The circuit to energize the SS relay includes a circuit breaker that is mechanically linked to the switch points and also a second circuit breaker that is mechanically linked to the lock mechanism in the switch machine.
		First, the track circuits beyond the interlocking limits (8TR and 14TR), which not included in the 2A controls, are included explicitly in the H relay leads.
	www.isi.edu /~braden/RRsigs/signal_circuit.txt (7589 words)

	ELECTRO-PNEUMATIC BLOCK SIGNAL SYSTEM (Site not responding. Last check: 2007-10-13)
		It consists in the use of danger signals at the beginning of specified lengths or blocks of track, each of which signals is to be kept at danger when a train is on the block protected by it until the block in question is free.
		A local battery of eight cells is arranged in circuit with the magnet of the semaphore and with the relay, so that when the latter is excited a current passes through the semaphore magnet, the local battery circuit being closed by the relay.
		The circuit closer closes the circuit when the piston is in the upward position or when the "Home" semaphore is at "Danger." This establishes a ground connection for the line leading to the "Distant" semaphore magnet below it, which connection is of zero resistance.
	www.catskillarchive.com /rrextra/sdbk.Html (1751 words)

	The Silver Stream Water-Race Tracks (Site not responding. Last check: 2007-10-13)
		Track conditions are variable: surfaces are uneven and sometimes muddy, streams and small slips must be crossed on foot, tracks have few markers, and some tracks are along exposed ridges where navigation is difficult in poor visibility.
		The tracks to the Picnic Area, Trig Q and the Bottom Weir are suitable for mountain buggies and are an easy (but long) walk for small children.
		This circuit is the same as the McRaes Weir Circuit, but continues along the water race on the Tunnel Track past a 262m tunnel (see 6 on map).
	www.cityofdunedin.com /city?page=rec_silverstr_tracks (2364 words)

	DC TRACK CIRCUITING (Site not responding. Last check: 2007-10-13)
		When a train occupies the track, the circuit is shorted to ground and the relay turns off.
		Consider D.C. track circuits - the D.C voltage is either strong enough to energise the relay, or it isn't - the relay is on or off.
		Automatic signals use the A.C. waveform of the track circuit ahead (the one they are protecting) to determine the coloured aspect to show.
	www.dvr.com.au /stinfo2.htm (932 words)

	Railway Research Centre: Fault Detection and Diagnosis of Railway Track Circuits
		The track circuit is, and will be for many years, the basis of most signalling systems around the world.
		Its purpose is to prove that a section of track is clear of all vehicles before allowing points to operate and signals to be cleared prior to the passage of a train.
		The track circuits provide indication to the signaller, via a signalling control panel, of the whereabouts of all vehicles on a section of line allowing the signaller to keep in step with train movements.
	www.railway.bham.ac.uk /fault.htm (473 words)

	Roxen Community: RFC 1793 Extending OSPF to Support Demand Circuits (Standards Track) (Site not responding. Last check: 2007-10-13)
		Even though a circuit's data-link connection may be closed at any particular time, it is assumed by the routing layer (i.e., OSPF) that the circuit is available unless other information, such as a discouraging diagnostic code resulting from an attempted data-link connection, is present.
		For demand circuits, this event should be mapped into the "discouraging diagnostic code" discussed previously in Section 1, and should not be generated when the data-link connection has been closed simply to save resources.
		Because the basic properties of the demand circuit functionality were presented in the previous example, this example will only address the unique issues involved when using both demand and non-demand circuits in parallel.
	community.roxen.com /developers/idocs/rfc/rfc1793.html (8746 words)

	Teamworks Karting Circuits - Track details and booking information
		Indoor circuit the largest indoor track in Scotland, with up to 12 karts on track at once.
		Indoor circuit featuring a flyover and tunnel, with up to 14 karts on track at once.
		Teamworks Karting's brand new state-of-the-art indoor circuit opened in October 2004 and features the UK's fastest indoor karts, on a purpose-built circuit in the heart of Birmingham.
	www.teamworkskarting.com /circuits.html (793 words)

	East Coast and West Coast circuits - NSX Prime
		Xavier is right, I have driven quite a few tracke on both the east and west coast and in between.
		There are two entirely different ways of considering whether a track is generally fast or slow: the speed down the straights (which is a function of their length) and the speed through the turns (which is a function of how tight they are, i.e.
		Most of the track would be 3-4 gear for an NSX I believe you would only go into second for the 4-5-6 complex which is short and maybe turn one if not up to pace.
	www.nsxprime.com /forums/showthread.php?t=44998 (2908 words)

	Re: High-voltage track circuits (Site not responding. Last check: 2007-10-13)
		In "Ronald BESDANSKY" writes: >An experiment was carried out about 30 years ago on the NSW National Park >line, using short pulses of about 100 volts instead of continuous DC or >low-frequency AC to feed track circuits.
		You are probably referring to Jeumont-Schneider track circuits, which use a pulsed signal swinging to about 100 volts positive and back to about 20 volts negative in each cycle (the period is about 1/2 a second).
		Actually, Mortdale yard (the new signalling) has J/S track circuits I think, as did Glenlee coal prep siding.
	www.railpage.org.au /ausrail/99december/msg02390.html (199 words)

	Alstom Audio Frequency Track Circuits AFTC Wayside
		Comprised of an Automatic Train Protection (ATP) module, two impedance bonds, and a track relay, AFTC provides train detection, speed command transmission, and bi-directional train-to-wayside communication (TWC).
		AFTC eliminates the need for buried cable and allows for the use of the compact and cost-effective WEE-Z bond.
		AFTC is a field-proven solution with installations on every major transit property in the United States.
	www.alstomsignalingsolutions.com /aftc.html (62 words)

	Trackdays at UK Race Circuits and Track Days Gift Experiences - UK Trackdays.com (Site not responding. Last check: 2007-10-13)
		A trackday will increase your awareness of vehicle dynamics in relation to your own car and basic driving errors will be identified and eradicated giving more feel for your vehicle within your own limits.
		You will receive the maximum amount of time on track with our unique format; 2 groups in the morning and open pit lane in the afternoon.
		Instruction is available from professional ARDS licensed instructors, full track side mechanical support is also available and we are members of the The Association of Track Day Organisers (ATDO).
	www.uk-trackdays.com (386 words)

	Discover Circuits - Track and Hold Circuits
		Bad links are removed and new circuits or schematics are added frequently.
		Sunday, March 12, 2006 10:37 AM Links to Circuits designed by others (off site):
		Calibrate scope jitter using a transmission-line loop: 09/20/01 EDN Design Ideas (added 1/05) Digital-clock-period jitter is the variation in the period of a clock cycle compared with a nominal (average of many cycles) clock period.
	www.discovercircuits.com /T/track.htm (200 words)

	Track Circuits definition - Railway Technology
		A track circuit is a track clear detection device consisting of an electrical circuit fed through the running rails of a section of track.
		This relay can detect if no train is present and can be used to switch power to a green signal light.
		Copyright 2006 SPG Media Limited a subsidiary of SPG Media Group PLC
	www.railway-technology.com /glossary/track-circuits.html (57 words)

	Fair Play Games - Formula De Circuits USA Track Pack #2 (Daytona, Atlanta, Lexington, Detroit) - Board Games and Card ... (Site not responding. Last check: 2007-10-13)
		Expansion for Formula De - The second offering in a premier series of USA Expansion Track Packs for Formula De showcasing 4 circuit tracks: Daytona, Atlanta, Lexington, and Detroit.
		Formula De Circuits 21 & 22 - Budapest & Nürburgring
		Formula De Circuits 23 - 26: USA Track Pack #1
	www.fairplaygames.com /gamedisplay.asp?gameid=2855 (192 words)

Try your search on: Qwika (all wikis)