Including Superconductivity Patents (Class 361/141)
  • Patent number: 6838964
    Abstract: Remote monitoring of superconducting magnet systems of various types, manufacturers, vintages, and so forth, via a magnet selector interface providing for configuring the monitoring system to the particular magnet system of interest. The technique provides for scalable analogue to digital conversion with integrated excitation circuitry for the input and output of magnet system sensors. Devices, such as remote terminal units and other data-logging technology may be adapted to remotely monitor primary indicators and secondary indicators of magnet system performance and related boil-off of helium. The technique provides earlier warning of impending failures in the magnet system, and thus facilitates predictive maintenance, reduces maintenance costs, reduces MRI downtime, reduces helium loss, and the like.
    Type: Grant
    Filed: November 26, 2003
    Date of Patent: January 4, 2005
    Assignee: GE Medical Technology Services, Inc.
    Inventors: Larry Keith Knight, Peter Chan
  • Patent number: 6793502
    Abstract: An electrical connector for use in a power module includes a first end portion for forming an electrical connection with a substrate, a second end portion, and a compliant portion situated between the first end portion and the second end portion. The compliant portion includes a compressed position and a decompressed position. The first end portion is configured for forming an electrical connection with a substrate if the compliant portion is in the compressed position.
    Type: Grant
    Filed: September 20, 2001
    Date of Patent: September 21, 2004
    Assignee: Ballard Power Systems Corporation
    Inventors: Scott Parkhill, Sayeed Ahmed, Fred Flett
  • Patent number: 6751075
    Abstract: A superconducting fault current controller/current controller employs a superconducting-shielded core reactor (SSCR) with a variable impedance in a secondary circuit to control current in a primary circuit such as an electrical distribution system. In a second embodiment, a variable current source is employed in a secondary circuit of an SSCR to control current in the primary circuit. In a third embodiment, both a variable impedance in one secondary circuit and a variable current source in a second circuit of an SSCR are employed for separate and independent control of current in the primary circuit.
    Type: Grant
    Filed: December 12, 2001
    Date of Patent: June 15, 2004
    Assignee: The University of Chicago
    Inventor: Yung S. Cha
  • Patent number: 6717781
    Abstract: A superconducting magnet electrical circuit is provided for quench protection. A superconducting coil assemblage is provided including a plurality of spatially separated main and secondary magnet coil portions. The main magnet coil portions are connected in series to form at least one main coil series circuit. The secondary magnet coil portions are also connected in a series to form at least one secondary coil series circuit. At least one temperature limiting circuit is also provided. The temperature limiting circuit may be a quench heater circuit or a quench resistor circuit. The temperature limiting circuit has a plurality of quench heaters or a plurality of quench resistors connected with the superconducting coil assemblage. A superconductive switch is coupled with the superconducting coil assemblage.
    Type: Grant
    Filed: September 25, 2001
    Date of Patent: April 6, 2004
    Assignee: GE Medical Systems Global Technology Company, LLC
    Inventors: Minfeng Xu, Xianrui Huang, Bu-Xin Xu, Jinhua Huang
  • Patent number: 6646836
    Abstract: A superconducting magnet circuit includes, besides a closed circuit formed of a plurality of unit superconducting coils 2a and 2b connected in series and a first persistent-current switch 4, a second persistent-current switch 5 which forms a closed circuit by connecting the ends of an arbitrary unit superconducting coil 2a, and is therefore made up of the two closed circuits, whereby their mutual induction suppresses the decay of the magnet apparatus' central magnetic field to provide extreme stability.
    Type: Grant
    Filed: March 1, 2001
    Date of Patent: November 11, 2003
    Assignee: Kabushiki Kaisha Kobe Seiko Sho
    Inventor: Masatoshi Yoshikawa
  • Patent number: 6639767
    Abstract: Self-quenching switching elements are connected in series in a semiconductor switching device. Snubber circuits including a diode, a capacitor, and a non-linear circuit are connected in parallel with the respective semiconductor switching elements. In the snubber circuit, the diode and the capacitor are connected in series, and the non-linear circuit is connected in parallel with the capacitor. The non-linear circuit includes an impedance element, a Zener diode, and a controlling semiconductor element and draws current through the controlling semiconductor element when applied voltage exceeds the Zener voltage of the Zener diode. The Zener voltage is larger than a divided voltage applied to the semiconductor element during a fault in a power system.
    Type: Grant
    Filed: November 8, 2001
    Date of Patent: October 28, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroshi Ito, Akihiko Iwata, Akihiro Suzuki
  • Patent number: 6624732
    Abstract: A superconducting magnet assembly comprises a superconducting magnet (1) which, under working conditions, generates a magnetic field in a working volume, the superconducting magnet being connected in parallel with a superconducting switch (3), the switch and magnet being adapted to be connected in parallel to a power source (4) whereby under working conditions with the switch (3) open, the magnet (1) can be energised by the power source to generate a desired magnetic field in the working volume following which the switch (3) is closed, characterised in that the assembly further comprises a resistor (5) connected in series with the switch (3), the resistor (5) and switch (3) being connected in parallel to each of the magnet (1) and the power source (4).
    Type: Grant
    Filed: September 10, 2002
    Date of Patent: September 23, 2003
    Assignee: Oxford Instruments Superconductivity Limited
    Inventors: Michael Norfolk Biltcliffe, M'hamed Lakrimi, Paul Antony Bruce Bircher
  • Patent number: 6524684
    Abstract: A current-limiting device contains at least one conductor track including high Tc superconductor material, on a support body. The conductor track is provided with a cover layer including an insulating plastic material, which includes a filler which increases the thermal conductivity. The thickness of the cover layer is greater than the thickness of the conductor track.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: February 25, 2003
    Assignee: Siemens Aktiengesellschaft
    Inventor: Björn Heismann
  • Publication number: 20020186520
    Abstract: Apparatus and method for controlling movement of an object through a medium using a magnetic field by combining the magnetic field of a primary electromagnetic coil having a central axis with the magnetic fields of a plurality of secondary electromagnetic coils having axes generally parallel to the central axis of the primary coil and positioned within the primary coil to produce an operational magnetic field by which movement of the object in a medium is controlled outside of the primary coil.
    Type: Application
    Filed: March 27, 2002
    Publication date: December 12, 2002
    Applicant: Florida State University Research Foundation, Inc.
    Inventor: Yehia M. Eyssa
  • Publication number: 20020171521
    Abstract: A flux pump of the rectifier type having high-temperature superconductors with switches, which can be controlled by way of a heater, in particular with trigger pulses D′ and self-stabilization in time with the rectifier is disclosed. An arrangement of the flux pump and a superconductor electromagnet, which may be supplied using the flux pump, may be integrated in a common cryostat housing.
    Type: Application
    Filed: December 27, 2001
    Publication date: November 21, 2002
    Inventor: Gunter Ries
  • Publication number: 20020121953
    Abstract: A device includes a flux pump and an electromagnet to be fed thereby for the production of highly constant magnetic fields of high field strength. In a flux pump of the rectifier type, switches used are MOSFETs. These MOSFETs include HTc superconductor material at operating temperatures. Preferably, the flux pump and a coil of the electromagnet are arranged in one and the same cryostat housing.
    Type: Application
    Filed: December 27, 2001
    Publication date: September 5, 2002
    Inventors: Gunter Ries, Florian Steinmeyer, Markus Vester
  • Patent number: 6241671
    Abstract: A system of navigating a magnetic medical device within that part of a patient located within an operating region of the system, the system comprising magnets, and preferably electromagnets, arranged to provide a magnetic field sufficient to navigate the magnetic medical device within the operating region. There are preferably three magnetic coils arranged in mutually perpendicular planes such that their axes intersect in the operating region. The magnetic coils are sized and arranged so that a patient can easily access the operating region to allow virtually any portion of the patient to be positioned within the operating region. The openness of the magnetic system allows access to the operating region by a bi-planer imaging system.
    Type: Grant
    Filed: December 14, 1998
    Date of Patent: June 5, 2001
    Assignee: Stereotaxis, Inc.
    Inventors: Rogers C. Ritter, Jeffrey M. Garibaldi, Charles Wolfersberger, Francis M. Creighton, Peter R. Werp, Bevil J. Hogg, Walter M. Blume
  • Patent number: 6236545
    Abstract: A current limiting device comprises a first superconducting element for connection in an electrical circuit. The superconducting element has a critical current density. A second superconducting element detects the onset of a fault condition. A coil is responsive to the second superconducting element to vary the relationship between the critical current density and the current carried by the first superconducting element so that the element transforms into a resistive state.
    Type: Grant
    Filed: June 25, 1997
    Date of Patent: May 22, 2001
    Assignee: Oxford Instruments PLC
    Inventors: Ian Leitch McDougall, Peter Hanley
  • Patent number: 6147844
    Abstract: A quench protection circuit for the series connected but spatially separated magnet coils of a superconducting magnet utilizes a parallel circuit of multiple heaters and reverse connected diodes shunting portions of the series connected magnets coils with the heaters physically positioned in thermal contact with other coils in the series circuit to thermally transfer a heat quenching action in any coil to all coils, along with a shunting current through the diodes to shunt peak currents upon coil quenching to avoid undesired spot temperature rise and enable controlled quenching of the entire magnet upon quenching of any coil.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: November 14, 2000
    Assignee: General Electric Company
    Inventors: Xianrui Huang, Phillip William Eckels
  • Patent number: 6128174
    Abstract: A method and apparatus for ramping current in an electromagnet in which a coil is used to generate the magnetic field provides rapid changes in the generated magnetic field. The method allows a change in current in the coil to be accomplished more rapidly than by applying a step change in voltage, when superconducting coils subject to quenching are used or when nonsuperconducting coils subject to other physical limitations are used. The method requires that both the current I(t) through the coil and the first derivative of the current vary with respect to time t during the ramping period, so that magnitude of the derivative of the current is higher when the magnitude of applied current is lower, lower when the magnitude of the applied current is higher. One variation of this method supplies (or removes) a constant amount of power from the magnetic field of the magnet, while another variation compensates for both self-generated eddy current losses and self-generated high field effects.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: October 3, 2000
    Assignee: Stereotaxis, Inc.
    Inventors: Rogers C. Ritter, Peter R. Werp, Michael A. Lawson
  • Patent number: 6108214
    Abstract: Plural units each composed of a metallic frame and a dielectric substrate mounted on the frame are stacked on one another, thereby forming a unitary case. A superconducting circuit such as a resonator is formed on an upper surface of the substrate, and a ground plane, made of a metallic material, preferably, a superconducting material, is formed on a lower surface of the substrate. The ground plane is exposed to a center opening of the frame, so that the ground plane of one substrate faces the superconducting circuit of another substrate which is stacked underneath the one substrate with a space therebetween. Thus, a plurality of the superconducting circuits are mounted in a compact unitary case.
    Type: Grant
    Filed: December 30, 1998
    Date of Patent: August 22, 2000
    Assignee: Advanced Mobile Telecommunication Technology, Inc.
    Inventor: Masashi Fuse
  • Patent number: 6094333
    Abstract: A control method allowing stable operation of a refrigerator conduction cooling type superconducting coil employing an oxide high temperature superconductor is provided. Thermal resistance between a refrigerator and a superconducting coil connected to a cooling stage of the refrigerator is obtained. From the obtained thermal resistance and the rated cooling capacity of the refrigerator, an effective cooling curve representing the relation between the temperature and calorific value is obtained. Operation of the superconducting coil which is energized while being cooled by the refrigerator is controlled such that the calorific value of the superconducting coil at a prescribed temperature does not exceed the effective cooling curve.
    Type: Grant
    Filed: October 22, 1998
    Date of Patent: July 25, 2000
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Takeshi Kato
  • Patent number: 6016094
    Abstract: In a superconducting short circuit current limiter for an AC power supply net including an iron core, a primary coil and a secondary short-circuited superconductive coil, both being magnetically coupled with the iron core but being arranged at a distance from each other, the iron core has gaps at opposite sides of the secondary coil for thermically uncoupling the secondary coil from the rest of the magnetic core and a tertiary coil is arranged closely adjacent the primary coil in a magnetically strongly coupled relationship therewith, and has a heat capacity sufficient to accommodate the joulean heat generated when a fault or short circuit occurs in the power supply net, and the iron core has an area of reduced cross-section which is so selected that it becomes magnetic flux saturated when the current in the primary coil exceeds a predetermined reaction current level.
    Type: Grant
    Filed: November 18, 1998
    Date of Patent: January 18, 2000
    Assignee: Forschungszentrum Karlsruhe GmbH
    Inventor: Jurgen Gerhold
  • Patent number: 5828291
    Abstract: A current limiting device including at least one superconductor and at least one nonsuperconducting shunt resistor in parallel with each superconductor. Each superconductor has a first main superconductor face in contact with a main shunt resistor face of a shunt resistor so as to form a compound conductor generally in the form of a meandering band having a band width greater than approximately 3.5 times the superconductor thickness. At least one insulator has opposing faces each in contact with a compound conductor. Multiple compound conductors are arranged such that current flows in opposite directions through adjacent compound conductors.
    Type: Grant
    Filed: July 30, 1996
    Date of Patent: October 27, 1998
    Assignee: ABB Research Ltd.
    Inventors: Thomas Baumann, Willi Paul, Jakob Rhyner
  • Patent number: 5654864
    Abstract: A control method permits the operation of multiple superconducting magnetic coils so as to move a magnetic object to precisely specified locations within the body under command of a physician-operator observing the motion with live fluoroscopic imaging fused with more detailed preoperative imaging of some other kind. A computer contains the preoperative images and the fluoroscopic images, as well as the means to effect changes in the coil currents so as to accomplish the desired magnetic object motion and positioning. The control method operates the coils in pairs on opposite sides of the body in a manner to minimize the necessary current changes, thus avoiding the quenching of the superconducting coils. Combinations of these pairs can execute motion of the magnetic object in any direction in an impulsive manner and with high precision. The method should function well and provide advantages with coils which are not superconducting as well.
    Type: Grant
    Filed: July 25, 1994
    Date of Patent: August 5, 1997
    Assignees: University of Virginia Patent Foundation, Stereotaxis, Inc.
    Inventors: Rogers C. Ritter, Michael A. Lawson, Robert G. McNeil
  • Patent number: 5650903
    Abstract: A superconductive-magnet electrical circuit includes a superconductive-coil assemblage having first, second, third, and fourth coil portions sequentially coupled together in series. A bipolar current-bypass electrical-circuit element (such as a pair of diodes opposingly coupled together in parallel) has:an impedance less than generally one-thousandth that of the coil portions; a first terminal coupled in parallel with the first and second coil portions; and a second terminal coupled in parallel with the third and fourth coil portions. A localized quench in one coil portion is quickly shared with the other coil portions to reduce damage from the quench. A resistor has a lead coupled in parallel with the second and third coil portions to limit quench voltages.
    Type: Grant
    Filed: November 30, 1995
    Date of Patent: July 22, 1997
    Assignee: General Electric Company
    Inventors: Dan Arthur Gross, David Charles Mack, Timothy John Havens
  • Patent number: 5642249
    Abstract: The present invention pertains to an electrical fault limiter. The fault limiter comprises a first magnetic core. There is also a second magnetic core opposing the first magnetic core. The fault limiter additionally comprises a third magnetic core adjacent the first magnetic core. Also, there is a fourth magnetic core opposing the third magnetic core and adjacent the second magnetic core. The electrical fault limiter also moreover comprises a rotor disposed between the first and second magnetic cores, and the third and fourth magnetic cores. The rotor is rotatable about a rotor axis. The first and second magnetic cores are disposed on a first side of the rotor axis and the third and fourth magnetic cores are disposed on a second side of the rotor axis. Each core has a first arm, a second arm and a body to which the first and second arms are connected. Each body has a superconducting bias coil disposed about it. Each arm has a conduction mode coil disposed about it.
    Type: Grant
    Filed: December 28, 1995
    Date of Patent: June 24, 1997
    Inventor: Stephen B. Kuznetsov
  • Patent number: 5596469
    Abstract: An electrical fault limiter having first, second, third, and fourth magnetic cores. The first magnetic core opposes the second magnetic core and is adjacent to the third magnetic core. The fourth magnetic core opposes the third magnetic core and is adjacent to the second magnetic core. A rotor is disposed between the first and second magnetic cores, and the third and fourth magnetic cores. The rotor is rotatable about a rotor axis. The first and second magnetic cores are disposed on a first side of the rotor axis and the third and fourth magnetic cores are disposed on a second side of the rotor axis. Each core has a first arm, a second arm and a body to which the first and second arms are connected. Each body has a superconduction bias coil disposed about it. Each arm has a conduction mode coil disposed about it.
    Type: Grant
    Filed: February 13, 1996
    Date of Patent: January 21, 1997
    Assignee: Power Superconductor Applications Co.
    Inventor: Stephen B. Kuznetsov
  • Patent number: 5523914
    Abstract: An inductive superconducting current storage (2), characterized in that it comprises an inner coil (4) wound from superconducting material and an outer coil (6) wound from superconducting material and disposed around the inner coil (4) in spaced manner therefrom, said inner coil (4) and said outer coil (6) in operation having current flowing therethrough in opposite directions so that the same magnetic flux as in the inner space (14) of the inner coil (4), but of opposite direction, is present in the annular space (12) between inner coil (4) and outer coil (6).
    Type: Grant
    Filed: December 28, 1993
    Date of Patent: June 4, 1996
    Assignee: Magnet-Motor Gesellschaft fur Magnetomotorisch Technik mbH
    Inventors: Werner Weck, Hermann Scholderle, Peter Ehrhart
  • Patent number: 5475560
    Abstract: A current limiting device using a superconductor limits a current flowing throu A c5 V pV:a current limiting coil, which mangetically couples to the superconductor. A control coil is provided to magnetically couple with the current limiting coil when the superconductor is switched to a normal conduction state. A variable control impedance is connected to the control coil to adjust a control current flowing through the control coil. The current limiting impedance value of the current limiting coil is adjusted by the value of the control impedance to obtain an adjustable value of the current flowing through the current limiting coil.
    Type: Grant
    Filed: May 29, 1992
    Date of Patent: December 12, 1995
    Assignees: Kogyo Gijutsuin, Denryoku Chuo Kenkyusho
    Inventors: Toshitada Onishi, Michiharu Ichikawa, Hiroyuki Kado, Yasuo Watanabe
  • Patent number: 5436606
    Abstract: The present invention provides a connection for feeding electricity to a transposed superconductive coil, the coil being placed in a cryostat and comprising a plurality of identical superconductive conductors, the free ends of which are distributed uniformly with cylindrical symmetry, the connection being constituted by two current leads each composed of a plurality of identical lead conductors each comprising a first end and a second end, the connection being characterized in that the number of the conductors is identical in each lead and equal to the number of the superconductive conductors in the coil, in that the conductors of the leads are disposed regularly and in parallel with the cylindrical symmetry about the axis of said coil, in that the leads are disposed coaxially and in that the first end of each lead conductor is connected to a respective superconductive conductor.
    Type: Grant
    Filed: February 3, 1994
    Date of Patent: July 25, 1995
    Assignee: GEC Alsthom Electromecanique SA
    Inventors: Christian Cottevieille, Gerard Bottini
  • Patent number: 5432666
    Abstract: A fault current limiter incorporating a high temperature superconductor material. During a fault condition, the superconductor material is allowed to operate above its critical temperature, providing sharply increased resistance. The fault current limiter can be sized and selectively cooled to provide a desired range of fault current limiting capability.
    Type: Grant
    Filed: January 22, 1993
    Date of Patent: July 11, 1995
    Assignee: Illinois Superconductor Corporation
    Inventor: James D. Hodge
  • Patent number: 5394130
    Abstract: A stable superconducting switch suitable for use in a conduction-cooled superconducting magnet includes a tape wound in a coil with the tape including an Nb.sub.3 Sn conductor sandwiched between stabilizing layers of copper, bronze or brass and wound in layers, with groups of layers separated by a partial layer of electrically conductive material.
    Type: Grant
    Filed: January 7, 1993
    Date of Patent: February 28, 1995
    Assignee: General Electric Company
    Inventors: Bu-Xin Xu, Raghavan Jayakumar, John J. Wollan
  • Patent number: 5387890
    Abstract: The present invention relates to a superconductive coil assembly which may be used particularly for a current limiter, the coil assembly comprising a plurality of coaxial cylindrical coils electrically connected in series, each coil comprising two windings of superconductive material electrically connected in parallel, arranged coaxially and wound in opposite directions, wherein in each coil, the windings are separated by a material which has a surface resistance in the radial direction lying in the range 10.sup.-5 .OMEGA..m.sup.2 to 10.sup.-2 .OMEGA..m.sup.2 at the temperature of the cryostat, and in which the strands which constitute the superconductive wires may themselves be covered with a layer of the same material.
    Type: Grant
    Filed: November 4, 1993
    Date of Patent: February 7, 1995
    Assignees: GEC Alsthom T & D SA, GEC Alsthom Electromecanique SA
    Inventors: Pascal Estop, Thierry Verhaege, Van Doan Pham, Alain Lacaze, Christian Cottevieille
  • Patent number: 5361055
    Abstract: A persistent switch system for protecting a large superconducting magnet coil during quench while providing the necessary different resistances needed for operation of the system in coil charging, discharging, persistent and quench modes while minimizing the heat load on the system refrigerator. The system includes a circuit having a combined persistent switch and shunt heater coil using two superconductor coils in parallel with a normal resistive thermal shunt coil thermally linked to the superconducting magnet coil. Switch superconducting coils can be driven normal to provide the switch resistance needed for efficient charging/discharging or the resistance needed to drive sufficient current through the shunt resistor coil during a quench. The quench operation uses shunt coil heating to enhance normal zone growth in the main coil, limiting the maximum quench temperatures reached.
    Type: Grant
    Filed: December 17, 1993
    Date of Patent: November 1, 1994
    Assignee: General Dynamics Corporation
    Inventor: Scott D. Peck
  • Patent number: 5355275
    Abstract: A variable impedance device comprises a coil (10) and an associated magnetic circuit (16) having a gap receiving a plate (20) of superconducting material which acts as a shield or barrier so that, while the plate (20) is in its superconducting state, magnetic flux is caused to traverse the gap via pathways substantially greater in length than the width of the gap. If a large current is passed through the coil (10), the plate (20) becomes resistive thereby presenting a substantially increased impedance to the current. The device may be used in current limiting applications, or other applications where a variable impedance is required.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: October 11, 1994
    Assignee: Imperial Chemical Industries PLC
    Inventors: Philip J. Goodier, Peter J. Davidson
  • Patent number: 5339062
    Abstract: Electrical energy is transferred or switched by selectively holding off the coupling of a magnetic field to a secondary inductive element (a coil) through a path which contains a high temperature superconductive element (HTS) which is capable of holding off the field when in its superconductive state notwithstanding that it is a high energy magnetic field. The HTS operates to hold off the magnetic field in accordance with the flux exclusion effect. When the HTS element is driven normal by heating with a laser pulse, the flux passes through the element and couples the field to the secondary, which may be connected to a load. A primary coil of superconducting material around the secondary coil can provide superconducting magnetic energy storage. The primary field is held off by HTS elements in the flux path to opposite ends of the secondary coil. These elements may be driven normal by laser pulses to transfer the stored magnetic energy to a load.
    Type: Grant
    Filed: July 8, 1993
    Date of Patent: August 16, 1994
    Assignee: The University of Rochester
    Inventors: William R. Donaldson, Deepnarayan Gupta, Alan M. Kadin
  • Patent number: 5334964
    Abstract: A device having cores of metal oxide ceramic (for example, Y-Ba-Cu-O) for limiting a short circuit current in power supply systems. The concept provides that a choke core, when operated at a rated current, is superconductive and its shielding currents keep the resulting inductance in the choke at a low level. In the event of an overload, the winding of the choke generates a correspondingly high magnetic field in the core which puts the core into the normally conducting state. This causes the shielding currents to disappear in connection with a rise in the resulting inductance, thus limiting the current. In order to realize a particularly high inductance in the normally conductive case, the superconductive choke core may be made hollow and may be filled at least in part with a ferromagnetic material.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: August 2, 1994
    Assignee: Licentia Patent-Verwaltungs-GmbH
    Inventors: Heinz Voigt, Roland Fischer, Rudolf Schneider
  • Patent number: 5334965
    Abstract: A superconductive load bearing support without a mechanical contact and vibration damping for cryogenic instruments in space. The levitation support and vibration damping is accomplished by the use of superconducting magnets and the "Meissner" effect. The assembly allows for transfer of vibration energy away from the cryogenic instrument which then can be damped by the use of either an electronic circuit or conventional vibration damping apparatus.
    Type: Grant
    Filed: June 15, 1993
    Date of Patent: August 2, 1994
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Benjamin P. Dolgin
  • Patent number: 5333087
    Abstract: A superconducting magnet apparatus has two or more divided superconducting coils successively arrayed in series and a magnetic shield. The divided superconducting coils arrayed in the axial direction are successively electrically connected in series, and protective diodes are connected between two connection points symmetrically-located with respect to the center of the serially-connected superconducting coil array as a reference.
    Type: Grant
    Filed: June 23, 1993
    Date of Patent: July 26, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Moriaki Takechi, Tatsuya Oue
  • Patent number: 5327015
    Abstract: An apparatus for producing an electrical impulse comprising a tube made of superconducting material; a source of magnetic flux is mounted about one end of the tube; a means for intercepting the flux is mounted along the tube; and a means for changing the temperature of the superconductor is mounted about the tube. As the tube is progressively made superconducting, the magnetic field is trapped within the tube and in so doing creates an electrical impulse in the means for intercepting. A reversal of the superconducting state produces a second pulse.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: July 5, 1994
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Kirk E. Hackett
  • Patent number: 5278380
    Abstract: A superconducting magnet coil is protected from local damage due to quenching by inductively driven heaters formed by heater strips embedded in the coil and connected in closed loops. A cold bypass diode shunting the coil winding commutates current out of the magnet when the voltage drop across the region of the coil which has gone normal exceeds the forward bias of the diode. This change in coil current induces sufficient current in the heater loops to cause the entire coil to go normal for uniform dissipation of stored energy throughout the magnet.
    Type: Grant
    Filed: December 3, 1990
    Date of Patent: January 11, 1994
    Assignee: Westinghouse Electric Corp.
    Inventor: Jerald F. Lowry
  • Patent number: 5267091
    Abstract: A levitating support and positioning system (10) is provided for orienting an electromagnetic energy reflecting assembly (40). System (10) includes a reflective member (60) supported by an annular ring (50) having a plurality of superconductors (70) disposed thereon. Ring (50) is levitated above a base surface (20) by means of a plurality of electromagnetic assemblies (30), each of the electromagnetic assemblies (30) corresponding to a respective one of the plurality of superconductive elements (70), whereby the magnetic fields generated by the electromagnetic assemblies (30) are repelled by the respective superconductive elements. The orientation of the support ring (50), and the reflector therewith, is adjusted by changing the relative magnetic field strength between each of the electromagnetic assemblies (30), allowing the reflector to be directed in both elevation and azimuth.
    Type: Grant
    Filed: July 18, 1991
    Date of Patent: November 30, 1993
    Assignee: Computer Sciences Corporation
    Inventor: Peter C. Chen
  • Patent number: 5241447
    Abstract: An electrical switch structure which employs superconductive material. A magnetizable core is encompassed by a body of superconductive material. The body of superconductive material has a superconductive state and a normal resistive state and can be placed in either state. The magnetizable core is also encompassed by at least one electrically conductive winding through which electrical current flows to create a magnetic flux within the magnetizable core. When the body of superconductive material is in its superconductive state current is induced therein by the magnetic flux in the magnetizable core. Current flow in the body of superconductive creates a magnetic flux in the magnetizable core which cancels the magnetic flux which is created by current flow in the electrically conductive winding.
    Type: Grant
    Filed: February 27, 1991
    Date of Patent: August 31, 1993
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: John P. Barber, Neal D. Clements, Russell L. Spyker
  • Patent number: 5225957
    Abstract: An improvement of a current limiting device using a superconductive coil. A trigger coil and current limiting coils are formed as a superconductive coil. A switching element which is actuated when a current limiting operation by the current limiting coil occurs, is connected in series to the trigger coil to immediately suppress heat generation by the trigger coil. When a quenching is detected by a detector, the trigger coil is disconnected and an additionally provided recovery coil is connected to speed up the recovery operation. A plurality of trigger coils connected in series may be used.
    Type: Grant
    Filed: May 22, 1990
    Date of Patent: July 6, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Kazuyuki Tsurunaga
  • Patent number: 5216568
    Abstract: A superconducting magnet device which is capable of protecting at the time of quenching a superconducting magnet divided into a plurality of sections comprises a superconducting magnet circuit which is formed by sequentially connecting in series coil pairs 1a, 1b, and 2a, 2b which are positioned symmetrically with respect to a ferromagnetic shield 6, and by connecting in parallel to the superconducting coils 1a, 1b and 2a, 2b superconducting coil protecting elements 3a and 3b which protect the superconducting coils 1a, 1b and 2a, 2b when the voltage at the ends of the coils has exceeded a predetermined value. If quenching occurs at the superconducting coils 1a, 1b and 2a, 2b, generation of an unbalanced electromagnetic force, a local electromagnetic force, etc., against the ferromagnetic shield 6 is prevented, so that the support structure for the superconducting coils and the ferromagnetic shield can be simplified.
    Type: Grant
    Filed: December 13, 1989
    Date of Patent: June 1, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Akihiro Harada, Akinori Yamasaki, Tatsuya Oue
  • Patent number: 5210674
    Abstract: A superconducting coil protective system comprises a quenching detector (QD) for detecting occurrence of a quenching in a superconducting coil (L) and generating a quenching signal indicative of the occurrence of the quenching. In response to the quenching signal, a voltage controller (VC) reduces an output voltage from a power source (PS) to zero or to a negative polarity. A current interrupter (CI) including a circuit breaker (CB) or a fuse (F) is connected in parallel to the superconducting coil (L) for allowing a first commutation of a current from the superconducting coil (L) to the current interrupter (CI) upon the reduction of the output voltage from the power source (PS). The system also comprises a protective resistor (RD) connected in parallel to the current interrupter (CI) for allowing a second commutation of the first-commutated current thereto upon the opening of the current interrupter (CI), whereby energy of the second-commutated current is dissipated in the protective resistor.
    Type: Grant
    Filed: May 29, 1991
    Date of Patent: May 11, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Satarou Yamaguchi, Tadanori Tsukamoto
  • Patent number: 5153803
    Abstract: A contact maker-breaker is disclosed in which the power contacts are associated in series with a superconducting element which is controlled by a heating element and which is structured so as to have a very high resistance following its controlled transition from the superconducting state to the normal state in response to a closing or opening order or following its intrinsic transition from the superconducting state to the normal state in response to a fault current, so that closing and opening of the power contacts takes place on the same leak current of a very low value.
    Type: Grant
    Filed: May 3, 1991
    Date of Patent: October 6, 1992
    Assignee: Telemecanique
    Inventors: Michel Rapeaux, Juan Aymami, Jacques Muniesa
  • Patent number: 5153804
    Abstract: A hybrid current limiter comprising a first winding of non-superconducting conductive material having a large number of turns and electrically connected in series with a superconductoring coil of low self-inductance and placed in a cryostat, and a second winding of non-superconducting conductive material having a small number of turns, said second winding being closely coupled with said first winding in such a manner as to obtain low overall inductance, the second winding being connected in parallel with the series circuit constituted by the first winding and the superconducting coil.
    Type: Grant
    Filed: April 24, 1991
    Date of Patent: October 6, 1992
    Assignee: GEC Alsthom SA
    Inventors: Van Doan Pham, Jean-Pierre Dupraz, Michel Collet, Yves Brunet, Pascal Tixador
  • Patent number: 5146383
    Abstract: A modular superconducting magnetic energy storage (SMES) inductor includes a plurality of vertically adjacent winding modules each comprising a number of serially connected concentric solenoid coils. Pairs of adjacent winding modules are connected in series to form paired winding modules each of which occupies a compartment in a sectioned dewar. Only a single shorting switch is provided for each winding module for use during an emergency dump of cryogenic fluid from the dewar. Adjacent paired winding modules can be connected in series by a single connector penetrating sectional plates between dewar compartments. Arrangements of bypass switches provide the capability of taking either a single winding module or a pair of winding modules out of service while the remaining winding modules and pairs of winding modules remain in service.
    Type: Grant
    Filed: June 20, 1990
    Date of Patent: September 8, 1992
    Assignee: Westinghouse Electric Corp.
    Inventor: James R. Logan
  • Patent number: 5121281
    Abstract: The invention relates to a circuit breaker for limiting a direct current and comprising a combination of first means including superconducting windings for limiting the current and second means for interrupting the residual current. The invention is applicable to interrupting high tension direct currents.
    Type: Grant
    Filed: December 10, 1990
    Date of Patent: June 9, 1992
    Assignee: GEC Alsthom SA
    Inventors: Van Doan Pham, Michel Collet, Mohamed Bekhaled, Thierry Verhaege
  • Patent number: 5067044
    Abstract: A quench detector for a superconducting coil is provided which utilizes an optical coupling and a rotary encoder. The presence of a resistive voltage in the superconducting coil created by a quench will cause a rotatable readout coil to move. Movement of the readout coil will be detected by light passing through or reflected by an optical encoder, which will interrupt or transmit light passing from one or more light sources towards one or more light sensors. Preferred embodiments utilize optic fibers for the light sources and sensors, which are unaffected by the high magnetic fields or hostile environment of the superconductor coil.
    Type: Grant
    Filed: March 5, 1990
    Date of Patent: November 19, 1991
    Assignee: Westinghouse Electric Corp.
    Inventors: George T. Mallick, Jr., James R. Logan, David Marschik
  • Patent number: 5051603
    Abstract: A power switching system for controlling the conductivity of a plurality of thyristors of the gate turn-off type (GTOs) which are connected in parallel between two power sources by gradually introducing a time compensation to force the times of turn-off of each of the thyristors toward matched values by determining the turn-off time during each conduction cycle and thereafter advancing or retarding the turn-off signal for the following conduction cycle to correct for the difference in turn-off times. A difference signal is generated between time of turn-off of an average current of the thyristors and the time of turn-off of an individual current in one of the thyristors from which a time advance or delay signal is added to the thyristor turn-off signal in response to the current flowing in a capacitor type integrator. This allows the turn-off times to reach a perfect match during periods in which the current is the same for several cycles.
    Type: Grant
    Filed: August 14, 1990
    Date of Patent: September 24, 1991
    Assignee: General Electric Company
    Inventor: Loren H. Walker
  • Patent number: 5011821
    Abstract: An electric power generating device includes a bundle of conductors which are placed in a magnetic field generated by north and south pole pieces of a permanent magnet. The magnetic field is shifted back and forth through the bundle of conductors by a pair of thin films of superconductive material. One of the thin films is placed in the superconducting state while the other thin film is in a non-superconducting state. As the states are cyclically reversed between the two films, the magnetic field is deflected according to the Meissner effect back and forth through the bundle of conductors to produce an electromagnetic force.
    Type: Grant
    Filed: April 21, 1989
    Date of Patent: April 30, 1991
    Assignee: Westinghouse Electric Corp.
    Inventor: Charley E. McCullough
  • Patent number: 4996472
    Abstract: The present invention provides a passive superconducting sensor for quench detection in a superconducting coil. The sensor consists of a first circuit electrically connected to two voltage taps of a superconducting coil. The first circuit uses nonsuperconducting components and preferably contains a resistive element. The first circuit is magnetically coupled to a second circuit by a hybrid transformer. The second circuit is superconducting and contains a readout coil and preferably a second hybrid transformer. The second hybrid transformer is magnetically coupled to a sense coil which detects flux changes in the superconducting coil. The readout coil is coupled to a readout device which measures changes in the current through the readout coil. The current in the readout coil can be made a function only of the resistance of the superconducting coil between the voltage turns and thus can be used to detect a quench.
    Type: Grant
    Filed: August 31, 1989
    Date of Patent: February 26, 1991
    Assignee: Westinghouse Electric Corp.
    Inventor: George T. Mallick, Jr.