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There is no active damping and the damping is only provided by the geometry of the track. Tests have shown that low frequency oscillations (1 Hz) occur and a US patent for mechanically damping the track itself (on
Inductrack II) was issued (7478598). The track is cut in segments and each segment
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However, at speed, the impedance of the coils increases, proportionate to speed, and dominates the composite impedance of the coil assemblies. This delays the phase of the current peak so that induced current in the track tends more closely to coincide with the field peaks of the magnet array. The
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Depending the application, lift to drag ratio at low speed or higher speed are favored. The three variation of the
Inductrack are designed for different purposes. The Inductrack I was designed for high speed trains. The lift to drag ratio lowers while speed increases. The Inductrack II has more
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variations in the field induce a voltage in the track coils. At low speeds the loops are a largely resistive impedance, and hence the induced currents are highest where the field is changing most quickly, which is around the
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The
Inductrack II variation uses two Halbach arrays, one above and one below the track, to double the magnetic field without substantially increasing the weight or area of the arrays, while also reducing drag at low speeds.
48:
There are three designs: Inductrack I, which is optimized for high speed operation, Inductrack II, which is more efficient at lower speeds, and
Inductrack III, which is intended for heavy loads at low speed.
124:
are used, levitation is achieved at low speeds. The test model levitated at speeds above 22 mph (35 km/h), but
Richard Post believes that, on real tracks, levitation could be achieved at "
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increases proportionately with speed which compensates for the faster rate of change of the field seen by the coils, thus giving a constant current flow and power consumption for the levitation.
72:. Above a minimum speed, as the velocity of the train increases, the levitation gap, lift force and power used are largely constant. The system can lift 50 times the magnet weight.
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track thus creates its own magnetic field which lines up with and repels the permanent magnets, creating the levitation effect. The track is well modeled as an array of series
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174:) or urban transport and uses a cantilevered track. The InducTrack III is designed for high load and cargo with track only partly cantilevered to sustain high loads.
478:
68:, based on technology used to levitate flywheels. At constant velocity, power is required only to push the train forward against air and electromagnetic
537:, Ziegler, Edward, "Track litz rungs and shorting bar design for urban maglev inductrack and method for making the same", issued 2004-11-09
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41:. The track can be in one of two configurations, a "ladder track" and a "laminated track". The ladder track is made of unpowered
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53:
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128:". Below the transition speed the magnetic drag increases with vehicle speed; above the transition speed, the magnetic drag
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814:
620:
589:, Post, Richard F., "Inductrack III configuration – a maglev system for high loads", issued 2013-11-12
550:, Post, Richard F., "Oscillation damping means for magnetically levitated systems", issued 2007-06-14
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is 200:1, far higher than any aircraft but much lower than classic steel on steel rail which reaches 1000:1 (
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524:, Post, Richard F., "Laminated track design for inductrack maglev systems", issued 2004-07-06
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576:, Reese, Eugene A., "Transit switching system for monorail vehicles", issued 2002-05-28
498:, Post, Richard F., "Magnetic levitation system for moving objects", issued 1998-03-03
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announced in March 2016 that they would be using passive
Inductrack systems for their titular
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system, using only unpowered loops of wire in the track and permanent magnets (arranged into
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Electric Cargo
Conveyor System with Inductrack, General Atomics, Final Report, October 2006
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8:
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511:, Post, Richard Freeman, "Inductrack magnet configuration", issued 2003-12-16
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AIP:Hyperloop
Transportation Technologies, Inc. Reveals Hyperloop™ Levitation System
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is developing
Inductrack technology in cooperation with multiple research partners.
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cables, and the laminated track is made out of stacked copper or aluminium sheets.
563:, Post, Richard Freeman, "Inductrack configuration", issued 2006-08-29
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Several maglev railroad proposals are based upon
Inductrack technology. The U.S.
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155:(NASA) is also considering Inductrack technology for launching space planes.
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capabilities of levitation at relatively low speed for use in individual (
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In "MagLev: A New Approach", above, section on "The Issue of Efficiency"
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creases with speed. For example, at 500 km/h (310 mph) the
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Lawrence Livermore National Laboratories: Richard Post contributions
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Inductrack (or Inductrak) was invented by a team of scientists at
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Media articles and technical reports on Inductrack, 1998 to 2005
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A New Approach for Magnetically Levitating Trains – and Rockets
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Toward More Efficient Transport: The Inductrack Maglev System
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16:
Passive, fail-safe electrodynamic magnetic levitation system
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598:
476:
The Inductrack Maglev system, Presentation on 10 Oct 2005
416:"Hyperloop taps into government research to float pods"
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Track To The Future: Maglev Trains On Permanent Magnets
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intense parts of the field, thus little lift produced.
96:; an electrical device made from loops of wire. As a
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as little as 1 to 2 mph (1.6 to 3.2 km/h)
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350:– Presented by Richard F. Post, 10 October 2005
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271:The Inductrack Approach to Magnetic Levitation
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153:National Aeronautics and Space Administration
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362:AIP:Halbach Arrays Enter the Maglev Race
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213:
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122:neodymium–iron–boron permanent magnets
54:Lawrence Livermore National Laboratory
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192:Hyperloop Transportation Technologies
140:). This occurs because the inductive
759:California–Nevada Interstate Maglev
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100:passes over the loops of wire, the
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31:electrodynamic magnetic levitation
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244:Richard F. Post (January 2000).
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456:S&TR article on Inductrack
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1:
815:Shanghai–Hangzhou Maglev Line
471:The International Maglevboard
445:General Atomics, Urban Maglev
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803:Qingyuan Maglev Tourist Line
702:High Speed Surface Transport
37:) on the vehicle to achieve
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10:
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654:Electromagnetic suspension
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183:is mechanically dampened.
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847:
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660:Electrodynamic suspension
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246:"MagLev: A New Approach"
765:Changsha Maglev Express
447:(Retrieved 28 May 2013)
165:Evolution of InducTrack
839:Lathen train collision
775:Incheon Airport Maglev
644:Linear induction motor
333:21 August 2007 at the
60:, headed by physicist
809:Shanghai Maglev Train
587:US patent 8578860
574:US patent 6393993
561:US patent 7096794
548:US patent 7478598
535:US patent 6816052
522:US patent 6758146
509:US patent 6664880
496:US patent 5722326
315:– Scott R. Gourley –
311:27 March 2014 at the
850:Proposals in italics
481:4 April 2023 at the
98:Halbach magnet array
84:comes from the word
832:Transport Accidents
649:Magnetic levitation
250:Scientific American
39:magnetic levitation
686:Lift-to-drag ratio
681:Eddy current brake
138:rolling resistance
134:lift to drag ratio
874:Rail technologies
856:
855:
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753:Birmingham Maglev
317:Popular Mechanics
267:Richard F. Post.
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791:Northeast Maglev
671:Magnetic bearing
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278:. Archived from
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252:. Archived from
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62:Richard F. Post
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375:on 6 July 2008
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285:on 7 July 2011
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637:Technologies
424:. Retrieved
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399:, retrieved
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370:the original
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287:. Retrieved
280:the original
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227:. Retrieved
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187:Applications
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712:Launch loop
229:7 September
115:RL circuits
76:Description
863:Categories
797:ODU maglev
727:Transrapid
707:Inductrack
379:22 October
225:. llnl.gov
202:References
102:sinusoidal
87:inductance
82:inductrack
58:California
20:Inductrack
196:Hyperloop
142:impedance
80:The name
43:Litz wire
28:fail-safe
732:SCMaglev
722:StarTram
717:Vactrain
666:Guideway
479:Archived
420:Engadget
331:Archived
309:Archived
289:17 April
93:inductor
695:Systems
489:Patents
178:Damping
24:passive
869:Maglev
785:M-Bahn
780:Linimo
630:Maglev
593:
580:
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426:11 May
741:Lines
662:(EDS)
656:(EMS)
422:. AOL
401:9 May
373:(PDF)
366:(PDF)
283:(PDF)
276:(PDF)
120:When
107:least
22:is a
428:2016
403:2016
381:2015
291:2010
231:2009
70:drag
172:PRT
90:or
56:in
865::
418:.
248:.
210:^
198:.
130:de
117:.
26:,
622:e
615:t
608:v
430:.
293:.
273:"
269:"
233:.
223:"
219:"
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