With Closed Core Interrupted By An Air Gap Patents (Class 336/178)
  • Patent number: 6002319
    Abstract: An inductance device comprises: an EE type ferrite core with an air gap at a center leg portion; a bobbin having at least three chambers wound by coils, said ferrite core being placed on said bobbin; and a shield coil formed by a first part and a second part of the coil, in which the first part is wound a chamber surrounding a peripheral portion of the air gap and the second part is wound the chamber in a reverse direction of the first part, the ends of the shield coil being short-circuited. In the inductance device with gap, the first and second parts of the coil are wound in the chamber surrounding the peripheral portion of the air gap in opposite direction each other, and the ends of the coil are shorted circuited. Thus, it is formed the shield coil for a leak magnetic flux from the air gap containing a component perpendicular to the main magnetic flux.
    Type: Grant
    Filed: September 1, 1998
    Date of Patent: December 14, 1999
    Assignee: TDK Corporation
    Inventor: Tooru Honma
  • Patent number: 5956073
    Abstract: Embodiments of the invention include a transformer device having a saturation region for limiting ingress noise and other noise. The transformer comprises a magnetic core, an input coil and an output coil arranged so that the output signal caused by the magnetic linkage between the input and output coils through the magnetic core is based on the magnitude of the input signal. According to an embodiment of the invention, the magnetic core includes a saturation region that limits the output signal regardless of the magnitude of the input signal once the saturation region reaches its saturation magnetization state. The saturation region comprises a reduced saturation magnetization level caused by a geometrically constricted region of the magnetic core or, alternatively, by a modified, magnetic-equivalent region having properties similar to a geometrically constricted region.
    Type: Grant
    Filed: December 19, 1996
    Date of Patent: September 21, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Sungho Jin, Joseph Michael Nemchik, Robert Bruce Van Dover, Wei Zhu
  • Patent number: 5926083
    Abstract: A static magnet dynamo including at least one permanent magnet having different poles; a first core comprising a soft magnetic material and which couples the different poles of the permanent magnet to form a closed magnetic path therein; a second core comprising a soft magnetic material which couples to the closed magnetic path via a paramagnetic material to form an open magnetic path; a magnetized coil wound around a portion of the first core where the closed magnetic path is formed; and an induction coil wound around a portion of the second core. A direction of a flux of the closed magnetic path is changed by applying an alternating voltage to the magnetized coil, generating an electromotive force in the induction coil by electromagnetic induction due changes in a flux of the open magnetic path induced by the change in direction of the flux of the closed magnetic path.
    Type: Grant
    Filed: February 10, 1998
    Date of Patent: July 20, 1999
    Inventor: Keiichiro Asaoka
  • Patent number: 5912553
    Abstract: An AC ferroresonant transformer includes a core having a closed loop path and a magnetic shunt assembly extending between portions of the core. A primary winding, a secondary winding and a tertiary winding are disposed on the core to link with magnetic flux in the core and the magnetic shunt. The tertiary winding includes terminals that are electrically isolated from the secondary winding. A first aspect of the present invention includes a tank capacitor connected to the tertiary terminals to form two LC circuits wherein a first LC circuit is a resonant circuit and a second LC circuit is a filtering circuit. Another aspect of the present invention is a method of operating an AC ferroresonant transformer proximate a knee of a B-H curve of the core, at minimal line voltage and full load, to reduce the generated harmonics.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: June 15, 1999
    Assignee: Schott Corporation
    Inventor: James F. Mengelkoch
  • Patent number: 5889373
    Abstract: A fluorescent lamp ballast utilizes a single a transformer for providing both tank inductance and current mode feedback to the ballast driver circuitry. The transformer has an "EE" core with inductor windings on the center legs and gate windings on one of the outer legs. The center leg is gapped to avoid magnetic core saturation and to adjust inductance to a desired value. Coupling can be adjusted further by gapping one or the other of the outer legs.
    Type: Grant
    Filed: December 30, 1996
    Date of Patent: March 30, 1999
    Assignee: General Electric Company
    Inventors: Rayette Ann Fisher, David Joseph Kachmarik, William Newell Schultz, Robert James Thomas
  • Patent number: 5883559
    Abstract: An adjustable asymmetric available saturation flux transformer for a horizontal deflection circuit of a CRT. The transformer includes a core having an asymmetric form, a linear compensation coil and a magnetic saturation control coil. The linear compensation coil is connected in series with a deflection coil of the horizontal deflection circuit. A current of the linear compensation coil can be adjusted to vary a current of the magnetic saturation control coil, so as to attain different effects of compensation as desired.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: March 16, 1999
    Assignee: Ko-Chong Yuan
    Inventor: Jiun-Haw Chan
  • Patent number: 5847634
    Abstract: A thin film inductive element according to this invention comprises an elongate conductor, and spaced apart magnetic strips that substantially surround the conductor, with dielectric material between the magnetic strips and the conductor. The inductive element can have relatively high inductance and low loss, can be used in linear form, meander on spiral form, or any other desired form, is suitable for use at RF frequencies, and can be integrated with conventional circuitry. Criteria for choosing the length of the magnetic strips and the thickness of the dielectric are disclosed.
    Type: Grant
    Filed: July 30, 1997
    Date of Patent: December 8, 1998
    Assignee: Lucent Technologies Inc.
    Inventors: Vladislav Korenivski, Robert Bruce van Dover
  • Patent number: 5844462
    Abstract: A magnetic core-coil assembly generates an ignition event in a spark ignition internal combustion system having at least one combustion chamber. The assembly comprises a magnetic core of amorphous metal having a primary coil for low voltage excitation and a secondary coil for a high voltage output to be fed to a spark plug. A high voltage is generated in the secondary coil within a short period of time following excitation thereof. The assembly senses spark ignition conditions in the combustion chamber to control the ignition event. The assembly is constructed from sub-assembly parts that can be manufactured with existing machines at reasonable cost.
    Type: Grant
    Filed: April 29, 1996
    Date of Patent: December 1, 1998
    Assignee: AlliedSignal Inc.
    Inventors: William R. Rapoport, Paul A. Papanestor
  • Patent number: 5844461
    Abstract: An isolation transformer comprises two core pieces mounted to cooperate to provide flux paths, one of the core pieces being shaped so that a central flux path is defined by a central leg of the core, at least two magnetically coupled windings surrounding the central flux path, and an isolation layer sandwiched between the windings.
    Type: Grant
    Filed: June 6, 1996
    Date of Patent: December 1, 1998
    Assignee: Compaq Computer Corporation
    Inventors: Richard A. Faulk, Eddie B. Braddy, Jr.
  • Patent number: 5841336
    Abstract: A magnetic core-coil assembly generates an ignition event in a spark ignition internal combustion system having at least one combustion chamber. The assembly comprises a magnetic core of amorphous metal having a primary coil for low voltage excitation and a secondary coil for a high voltage output to be fed to a spark plug. A high voltage is generated in the secondary coil within a short period of time following excitation thereof. The assembly senses spark ignition conditions in the combustion chamber to control the ignition event. The assembly is constructed from sub-assembly parts that can be manufactured with existing machines at reasonable cost.
    Type: Grant
    Filed: January 27, 1997
    Date of Patent: November 24, 1998
    Assignee: AlliedSignal Inc.
    Inventors: William R. Rapoport, Paul A. Papanestor
  • Patent number: 5821638
    Abstract: A flux concentrator 1300 for an inductive power transfer system is made up from rectangular fingers 1301 of ferrite material held in close contact by compression means to form a large shock resistant core. The fingers are positioned at right angles to a primary conductor 1312 to concentrate the horizontal component of the magnetic flux through the flux concentrator. The fingers include bridge sections 1309 adapted to support pick-up coil windings 1307. The flux concentrator is covered by a conducting sheet of aluminum 1311 on the side of the magnetic core far away from the source of magnetic flux.
    Type: Grant
    Filed: May 16, 1996
    Date of Patent: October 13, 1998
    Assignee: Auckland UniServices Limited
    Inventors: John Talbot Boys, Andrew William Green
  • Patent number: 5821844
    Abstract: A D.C. reactor has a core structure having two opposed cores separated by a magnetic gap, to form a closed magnetic circuit. A coil is wound on one or both of the cores. A pair of permanent magnets for biasing are disposed on the core structure. The bias flux generated by the permanent magnets and the flux generated by the coil to flow in opposite directions. Bypass means for causing the bias flux generated by the permanent magnets to bypass the magnetic gap are provided. In an embodiment the core structure comprises an E-shape core and an I-shaped core, the magnetic gap is defined between a center leg of the E-shaped core and the I-shaped core, the coil is wound on the center leg of the E-shaped core, and each permanent magnet is shaped as a rectangle and disposed on both side surfaces of the center leg of the E-shaped core.
    Type: Grant
    Filed: August 5, 1996
    Date of Patent: October 13, 1998
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Ryuichirou Tominaga, Noriaki Iwabuchi, Michihiko Zenke
  • Patent number: 5821845
    Abstract: Proposed is a reduction of variance in electromagnetic noise eliminating effect with signal conductors arranged in a flat cable to which an electromagnetic noise absorber is attached. The electromagnetic noise absorber is provided with a plate magnetic body and a U-shaped magnetic body. Since the width of the plate magnetic body is smaller than the interval between the side walls of the U-shaped magnetic body, the plate magnetic body can be accommodated in the U-shaped magnetic body, with a clearance formed between the end portions of the plate magnetic body and the side walls of the U-shaped magnetic body. The impedance in the vicinity of the clearance is decreased, and the difference in impedance between the end portions and the middle portion of the electromagnetic noise absorber is decreased. Therefore, a variance in the electromagnetic noise eliminating effect with signal conductors of the flat cable is made small.
    Type: Grant
    Filed: July 25, 1997
    Date of Patent: October 13, 1998
    Assignee: Kitigawa Industries Co., Ltd.
    Inventor: Yoshinori Ohashi
  • Patent number: 5815062
    Abstract: In the magnetic core including a first leg portion around which a wire is wound, a second leg portion for circulating a magnetic flux generated in the first leg portion, and a web portion connecting the first leg portion and the second leg portion, a magnetic gap is provided in a rear area extending from the root of the first leg portion. With the magnetic gap, a magnetic flux leaking outwardly from a rear area extending from the root of the first leg portion is drastically reduced.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: September 29, 1998
    Assignees: Hitachi Metal, Ltd., Hitachi Ferrite Electronics, Ltd.
    Inventors: Norikazu Koyuhara, Youichi Yamamoto, Toshihiko Tanaka
  • Patent number: 5783984
    Abstract: In a prefer embodiment, an integrated transformer and inductor on a singe core structure to provide an impedance matching function and an inductor in series with the transformer's secondary which includes: a transformer core structure having a primary leg, a secondary leg, and a center leg containing an air gap, said center leg disposed parallel to said primary leg and secondary leg, whereby said air gap provides control of said inductor value; a primary winding on said primary leg; and a secondary winding on said secondary leg.
    Type: Grant
    Filed: June 16, 1995
    Date of Patent: July 21, 1998
    Assignee: Hughes Electronics
    Inventor: Carl Edward Keuneke
  • Patent number: 5760670
    Abstract: The present invention relates to a tranformer core structure, which includes a rectangular frame core having two long sides and two short sides, with one short side having a recessed part and the other short side being closed to form a junction surface of magnetic path; and a strip core disposed in the rectangular frame core through the recessed part, and having a length similar to that of said long side of said rectangular frame core, but having a width slightly less than that of said recessed part, wherein adjustment of the inductance of the structure is accomplished by moving said strip core along said recessed part to adjust a gap between one end of said strip core and said junction surface of magnetic path.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: June 2, 1998
    Assignee: Delta Electronics, Inc.
    Inventors: Ming Yeh, Y. J. Chen, H. B. Chan, Antony Du, Albert Chang
  • Patent number: 5754087
    Abstract: A high-voltage transformer for a television display device having a core made of two core parts. One end of a core limb is chamfered or rounded on the outside such that the contact region is distal from the outer edge of the core limb. The end of the core limb is preferably provided with a bevel.
    Type: Grant
    Filed: March 27, 1996
    Date of Patent: May 19, 1998
    Assignee: Deutsche Thomson Brandt GmbH
    Inventor: Walter Goseberg
  • Patent number: 5751205
    Abstract: A transformer to achieve a precise amplitude for the operating voltages produced by the auxiliary windings, and such that the construction and production of the transformer are simplified. An auxiliary winding is split into a plurality of winding elements disposed in different chambers of a chamber-type coil former. One of the chambers is disposed in the region of the air gap of a U/I core or of a U/U core, the two U-core halves having parallel limbs of different lengths.
    Type: Grant
    Filed: February 15, 1996
    Date of Patent: May 12, 1998
    Assignee: Deutsche Thomson Brandt GmbH
    Inventor: Walter Goseberg
  • Patent number: 5748013
    Abstract: A magnetic core includes a body made of polycrystalline ceramic and at least one localized gap made of a composite magnetic material. The gap may be preferably fixedly joined to the body by bonding or molding. The magnetic core has applications in inductors or transformers. The inductor preferably has a coil located on the body, which coil is preferably made of multistranded enameled wires.
    Type: Grant
    Filed: October 23, 1996
    Date of Patent: May 5, 1998
    Assignee: Thomson-CSF
    Inventors: Fran.cedilla.ois Beauclair, Jean-Pierre Delvinquier, Richard Lebourgeois, Michel Pate, Claude Rohart
  • Patent number: 5748064
    Abstract: A low profile reactor or inductor with a spiral type of winding which conducts a high level of current for its allotted size. The present invention provides a unique two piece bobbin design in order to produce a reactor of this type in a small space with small dimensional tolerances. The two piece bobbin is designed to provide a connection to the interior terminal end of the reactor coil, which is normally difficult to accomplish because of the limited small size and area. A first bobbin piece defines a first bobbin flange, and the second bobbin piece defines a center post, providing a cylindrical winding surface, and a second bobbin flange. The center post is provided with a first recessed groove in the winding area, and the second bobbin flange is provided with a second recessed groove. A start terminal is positioned in the first and second recessed grooves below the surfaces thereof.
    Type: Grant
    Filed: February 22, 1996
    Date of Patent: May 5, 1998
    Assignee: Northrop Grumman Corporation
    Inventors: Robert E. Smeenge, George F. Pierce, Samuel J. Cicero
  • Patent number: 5745367
    Abstract: An FBT, its inductance adjusting method and a device capable of adjusting a gap between the top and bottom cores features a stable inductance value required for the FBT even without requiring a separate spacer between the top and bottom ferrite cores. An adhesive agent is applied to top end of a coupling portion of the bottom core provided within the low voltage bobbin, and a predetermined inductance value between the bottom core and the top core is obtained by a hardening of the adhesive agent therebetween without having a separate gap maintaining arrangement. The inductance value within the FBT can be precisely adjusted even without requiring a separate spacer at the gap portion between the top and bottom ferrite cores of FBT. In addition, it is not necessary to use a U-clip for fixing the top and bottom ferrite cores.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: April 28, 1998
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventor: Sang Yeob Cha
  • Patent number: 5731666
    Abstract: A two-winding, integrated-magnetic EMI filter provides damped common-mode and differential-mode inductances. The preferred embodiment of the filter has a magnetic core structure that incorporates a high-permeability C-core, a high-permeability I-core, and a low-permeability, lossy shunt. The three core pieces are assembled so as to form a structure that, similar to an E-I configuration, has two winding windows. The loss in the shunt aids in dissipating noise and it diminishes the effects of unwanted parasitic resonances by providing damping for the differential-mode inductance. Damping for the common-mode inductance is provided by losses in the C and I core pieces. Varying the reluctance of the shunt allows the differential-mode inductance to be adjusted separately from the common-mode inductance in order to tune the filter to remove desired noise frequencies. Another embodiment of the invention incorporates a high-permeability toroid core and a low-permeability, lossy shunt.
    Type: Grant
    Filed: March 8, 1996
    Date of Patent: March 24, 1998
    Assignee: Magnetek Inc.
    Inventors: Don V. Folker, Bryce L. Hesterman, Dan Soule, George W. Mortimer
  • Patent number: 5729505
    Abstract: An ignition device for an internal combustion engine in which an iron coil is easily and securely grounded. In the ignition device, an ignition coil includes an iron core formed by laminating a plurality of cut steel plates; a primary coil wound around the iron core; a secondary coil wound around the primary coil; and a conductive plate being arranged between the iron core and a primary bobbin of the primary coil, having a contact surface with which sections of the steel plates are in contact and being electrically connected to a ground terminal of an external terminal.
    Type: Grant
    Filed: February 23, 1996
    Date of Patent: March 17, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shigemi Murata, Mitsuru Koiwa
  • Patent number: 5726615
    Abstract: Disclosure is made of an integrated-magnetic apparatus, comprising: winding structure for insulatingly carrying at least two generally flat, laterally offset and spaced apart electrical windings of a power converter around an aperture; a core having a flat exterior face, an interior cavity and an un-gapped core-column that is located within the cavity and that passes through the aperture of the winding structure; flat-sided surface carried by the core and forming an interior chamber that is located adjacent to the flat face of the core and forming a core-column that has a gap and that is located within the chamber; and structure, located around the gapped core-column, for carrying a third electrical winding of the power converter. The first two electrical windings are substantially located within the cavity and are adapted to be transformingly coupled together through the core.
    Type: Grant
    Filed: March 24, 1994
    Date of Patent: March 10, 1998
    Inventor: Gordon E. Bloom
  • Patent number: 5719546
    Abstract: An inductive coupler forming a closed magnetic circuit by mating a primary core assembly having a primary winding and a secondary core assembly having a secondary winding for transferring electrical power from the primary winding to the secondary winding by electromagnetic induction. A thin magnetic protective sheet having high permeability is attached to the mating surfaces of at least one of the primary and secondary core assemblies or placed to be held by the core assemblies. The magnetic sheet can protect the mating surfaces of ferrite cores, if such cores are used, from breakage by absorbing and dispersing the shock of impact caused when the mating surfaces are abutted against each other to close the cores. Provision of a slit or slits in the magnetic protective sheet can reduce eddy currents flowing in the magnetic sheet.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: February 17, 1998
    Assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
    Inventors: Makoto Ito, Kazuyoshi Takeuchi, Goro Asahi
  • Patent number: 5694103
    Abstract: An improved laminated ferromagnetic FIG. 8 power meter core is provided. The core is fabricated from a plurality of ferromagnetic plates and is formed in the general shape of a FIG. 8. The central leg of the core has a cross-sectional area that is larger than the cross-sectional area of other parts of the core. The core gap, in which a Hall-effect sensor is located, has gap faces with chamfered or rounded over edges to reduce fringing and bypassing effects. The core is formed without discontinuous corners that can result in local saturation and, in use, accommodates electrical power conductors in an over-under looping relationship through the openings of the core to provide a more homogeneous magnetic flux within the core and thus more reliable metering. The overall result is a core with a higher saturation point and thus a wider dynamic range than prior art cores.
    Type: Grant
    Filed: April 25, 1996
    Date of Patent: December 2, 1997
    Assignee: Schlumberger Industries, Inc.
    Inventors: R. Wendell Goodwin, David N. Makinson, Richard Timko
  • Patent number: 5685065
    Abstract: An inner core for an ignition coil is inserted into a bobbin, around which a primary winding and a secondary winding are disposed. An outer core is inserted into a housing to form a magnetic circuit with the inner core. A magnet member, which is made of a permanent magnet material such as Sm.sub.1 Co.sub.5, is connected to the inner core. The bobbin, which is assembled with the inner core, the magnet member, the primary and secondary windings, is inserted into the housing, with the magnet member positioned between the inner core and the outer core, and then the inside of the housing is molded by a synthetic resin. Thereafter, the magnet member is magnetized to provide a predetermined magnetic force. The magnet member may be molded by Sm.sub.1 Co.sub.5 to form a plate having a thickness of 1.5 mm and more.
    Type: Grant
    Filed: July 26, 1995
    Date of Patent: November 11, 1997
    Assignee: Aisan Kogyo Kabushiki Kaisha
    Inventors: Toshiro Suzuki, Koji Yoshikawa
  • Patent number: 5675306
    Abstract: A method and apparatus to amplify the magnetic field in an electromagnetic circuit is provided. Amplification factors of several orders of magnitude may be obtained. The system is applicable to a number of different systems, including melt levitation and electromagnetic pumping and propulsion. One embodiment of the invention uses a non-conducting permeable core wound around a dielectric core. An alternating voltage source is connected to a solenoid which is wound around a section of the permeable core. The permeable core has a gap within which a flux concentrating cold crucible is provided. Melt levitation processing takes place within the cold crucible.
    Type: Grant
    Filed: May 18, 1995
    Date of Patent: October 7, 1997
    Inventor: Rodolfo E. Diaz
  • Patent number: 5656983
    Abstract: An inductive coupler forming a closed magnetic circuit by mating a primary core assembly having a primary winding and a secondary core assembly having a secondary winding for transferring electrical power from the primary winding to the secondary winding by electromagnetic induction. A thin magnetic protective sheet having high permeability is attached to the mating surfaces of at least one of said primary and secondary core assemblies or placed to be held by the core assemblies. The magnetic sheet can protect the mating surfaces of ferrite cores, if such cores are used, from breakage by absorbing and dispersing the shock of impact caused when the mating surfaces are abutted against each other to close the cores. Provision of a slit or slits in the magnetic protective sheet can reduce eddy currents flowing in the magnetic sheet.
    Type: Grant
    Filed: April 25, 1995
    Date of Patent: August 12, 1997
    Assignee: Kabushiki Kaisha Toyoda Jidoshokki Seisakusho
    Inventors: Makoto Ito, Kazuyoshi Takeuchi, Goro Asahi
  • Patent number: 5587694
    Abstract: Two sets of a combination of an iron core formed of laminated strip-shaped electromagnetic steel plates and a coil are arranged in parallel, and these are abutted via core gap spacers against two iron cores formed of laminated trapezoidal electromagnetic steel plates, so that a square-shaped magnetic path is formed. Two outside iron cores of the four iron cores are coupled and fixed with metal fittings. With such an arrangement, the coil is divided into two, with increased surface areas of the coils and therefore an improved cooling characteristic. Further, since the electromagnetic steel plates used for the iron cores can be formed into simple shapes, electromagnetic steel plates of various sizes can be easily manufactured, so that iron cores of optimum dimensions can be provided, optionally depending on the type of the reactor.
    Type: Grant
    Filed: December 28, 1994
    Date of Patent: December 24, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tetsuya Minato, Toshimitsu Yonehara, Junichi Teranishi, Shohei Toyoda, Toshiaki Bito, Kazushige Takashima
  • Patent number: 5574418
    Abstract: A three-phase autotransformer improving balance of three-phase voltages and currents. An iron core has three legs corresponding to the three phase. A common winding and/or a serial winding of each phase includes three coils. Two of the three coils are wound on the same leg associated with the phase of the coils, and the other one coil is wound on another leg. The two coils and the other one coil are connected in series to generate magnetic flux in the opposite directions. Since the common winding and/or the series winding includes coils which are wound on different legs associated with different phases, and which generate flux in opposite directions, the balance of three-phase input voltages and currents, and output voltages and currents is automatically maintained.
    Type: Grant
    Filed: October 19, 1994
    Date of Patent: November 12, 1996
    Inventor: Mitsuya Matsumura
  • Patent number: 5559487
    Abstract: A conductive winding electrically isolated by reflowable material which is incorporated into a transformer further including individual layers of electrical insulation material. The transformer is formed in a layered configuration wherein isolation requirements set forth by safety certification agencies are met through the use of the reflowable material and insulation layers.
    Type: Grant
    Filed: May 10, 1994
    Date of Patent: September 24, 1996
    Assignee: Reltec Corporation
    Inventors: Jerry L. Butcher, Harold E. Lee
  • Patent number: 5539369
    Abstract: An induction device has an elongated core made of two or more uniform ferromagnetic spaced-apart toroids. A first winding around the core creates an inductor. When the induction device includes a second winding, a transformer is created. The transformer acts as a powercord transformer when the exposed ends of one winding are available at one end of the elongated core for connection to a source of alternating current and the exposed ends of the other winding are available at the other end of the core for connection to a load. An inductor with a single-turn winding can be constructed by first forming the core by stacking two or more ferromagnetic toroids end-to-end and spaced apart, then threading two wires through the core center and placing two wires outside the core and connecting the ends of the wires to create the winding. A transformer can be constructed by first following the steps to create an inductor. A second winding is then created in a similar manner as the first winding.
    Type: Grant
    Filed: September 28, 1994
    Date of Patent: July 23, 1996
    Assignee: International Business Machines Corporation
    Inventors: Edwin J. Selker, Jason M. Jacobs, Robert J. Kelley, Joseph D. Rutledge
  • Patent number: 5537036
    Abstract: A high frequency magnetic property measuring apparatus for soft magnetic film includes a magnetic detection device for detecting the intensity of magnetization in a sample material, a high frequency magnetic field generator for generating magnetic field, a power source for supplying current to the magnetic field generator, and a data processing device for getting high frequency magnetic parameters of the sample by using a detection signal output from the magnetic detector. The magnetic field generator is made up of a plane-shaped coil of a conductor having a configuration in which both ends of the plane-shaped coil are closed to form a cavity as a second internal cavity in which the detector is placed. The magnetic detector is made up of a plane-shaped coil of a conductor having a configuration in which both ends of said plane-shaped coil are closed to form a cavity as a first internal cavity in which the sample material is placed. The magnetic detector is placed in the magnetic field generator.
    Type: Grant
    Filed: September 8, 1993
    Date of Patent: July 16, 1996
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshiro Sato, Tetsuhiko Mizoguchi
  • Patent number: 5528113
    Abstract: A loosely coupled inductive power transfer system suitable for transferring power to a mobile conveyer platform or a vehicle has pick-up coils wound on flux concentrator(s). One or more large flat horizontal ferrite cores 607, 608 are used to concentrate the horizontal component of magnetic flux from an extended volume into one or more secondary or pick-up coils 613. Each shock-resistant core comprises an array of many individual strips of ferrite held in close contact. One, more usually two, or perhaps more resonant pick-up windings are wound about each core and each winding has a shorting switch (within 602, 603 . . . ) placed across it. A controller 601 connects a controlled output voltage on to an output bus 605, 606 from the best-placed pick-up winding on any one core at any moment, while holding the others in a shorted hence inactive state.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: June 18, 1996
    Inventors: John T. Boys, Andrew W. Green
  • Patent number: 5525951
    Abstract: Two coils 3a, 3b are wound over adjacent portions of a first magnetic core having two closed magnetic circuits and a second magnetic core. The winding directions of the two coils are set so that the magnetomotive forces generated by both coils may cancel each other in the second magnetic core. The magnetic fluxes flowing in the first magnetic core decrease the higher harmonics of an input current of the power source circuit, while the magnetic fluxes flowing in the second magnetic core 2 decrease the noise between the line and the ground. That is, the choke coil performs the function of choke coil and the function of noise filter at the same time.
    Type: Grant
    Filed: June 22, 1993
    Date of Patent: June 11, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shuji Sunano, Yusuke Ikeda, Tsunetsugu Imanishi, Tatsuo Maeoka
  • Patent number: 5521572
    Abstract: An air-coupled current transformer is provided with a primary current conductor and two secondary coils connected such that the emf induced in each coil by an external disturbing magnetic flux is subtractive, whereas the emf induced by the current in the primary is additive. Two ferromagnetic core pieces enhance the rejection of the emf induced by the disturbing flux. Ceramic spacers are inserted into air gaps between the core pieces for maintaining the gaps fixed to keep the scale factor of the transformer independent of temperature.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: May 28, 1996
    Assignee: Schlumberger Industries, Inc.
    Inventors: R. Wendell Goodwin, Charles W. Roberts
  • Patent number: 5506764
    Abstract: An improved electrical power converter is disclosed. The electrical power converter utilizes a step-gapped power transformer having a ferromagnetic core, a primary winding, and one or more secondary windings. The ferromagnetic core is step-gapped such that it has a continuous portion and a gapped portion. A power switch, preferably a MOSFET, alternately couples an input voltage across the primary winding of the transformer, inducing voltage pulses across the secondary windings that are filtered to produce one or more output voltages. The gate terminal of the MOSFET is preferably driven by the voltage induced across a tertiary winding of the transformer.
    Type: Grant
    Filed: January 31, 1994
    Date of Patent: April 9, 1996
    Assignee: Astec International, Ltd.
    Inventors: Chau H. Hon, Cheung C. W. Jonathan
  • Patent number: 5477203
    Abstract: An ignition coil assembly for an internal combustion engine includes a primary coil, a secondary coil, at least one bobbin, a core, a first resin member and a casing. The primary coil and said secondary coil are wound on the bobbin. The core has core elements with a gap there-between through which the primary and secondary coils are magnetically coupled to one each other. The casing accommodates the primary and secondary coils, the bobbin and the core. And the first resin member covers a part of the core elements, the part which are confronted with said secondary coil, and the first resin member is accommodated in the casing.
    Type: Grant
    Filed: July 8, 1994
    Date of Patent: December 19, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Nobuyuki Sawazaki, Shigemi Murata, Mitsuru Koiwa, Yutaka Ohashi
  • Patent number: 5446435
    Abstract: The magnetic circuit (1) is made in a single piece or consists of a stack of identically-shaped sheets. The height (H) of the air gap (2) is greater than the thickness (E) of a coil (5), enabling said coil to be inserted through the air gap. This structure is easily assembled during the mass production of current sensors which use such circuits.
    Type: Grant
    Filed: April 30, 1993
    Date of Patent: August 29, 1995
    Assignee: Liaisons Electroniques-Mecaniques LEM S.A.
    Inventor: Marcel Etter
  • Patent number: 5444427
    Abstract: An engine igniting coil device comprising a coil case with a plurality of coil units disposed therein and integrally potted with insulating resin, which is featured by provision with a coil cover that fits in the coil case and can mount therein high-voltage and low-voltage terminal sockets for the coil units, allowing the assembly of the electrical connections of the coil units in optimal conditions.
    Type: Grant
    Filed: September 20, 1993
    Date of Patent: August 22, 1995
    Assignee: Toyo Denso Kabushiki Kaisha
    Inventors: Yasuhiko Ida, Makoto Sakamaki
  • Patent number: 5440225
    Abstract: The invention pertains to a core for a coil device of a switching power supply which can avoid accidental breakage of the portion where the core cross-sectional area narrows. When one core segment is rotated 180 degrees about its center axis in the long direction of one leg 2, the projection 51 of one core segment 1A and the projection 52 of another core segment 1B, and the indentation 61 of the one core segment 1A and the indentation 62 of the other core segment 1B are aligned so as to mutually overlap. The characteristics of a coil device can be controlled by the contacting surface areas of both core segment projections or by spacing between the projections. Since the cross-sectional area of each core projection can be made wider, accidental breakage of the core projection does not occur easily.
    Type: Grant
    Filed: February 24, 1993
    Date of Patent: August 8, 1995
    Assignee: Toko Kabushiki Kaisha
    Inventor: Hideki Kojima
  • Patent number: 5426409
    Abstract: A current controlled variable inductor comprises a magnetically saturable E" core having outer limbs each joined to a center limb by connecting limbs. A staggered series of flux bridges and air gaps are formed into alternating sides of the outer limbs. A bias winding on the center limb magnetically couples a direct current into the core to vary the inductance of a signal winding on the outer limbs. A secondary winding magnetically couples an output voltage from the core for application of the inductor as a tunable transformer.
    Type: Grant
    Filed: May 24, 1994
    Date of Patent: June 20, 1995
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Leopold J. Johnson
  • Patent number: 5422620
    Abstract: The so-called delta-phi transformer makes use of the effects of various core materials and air gap sections in the cores on the magnetization curves of core materials. It consists of at least two magnetically separated cores, designated source core SK and regulating core RK, which possess different magnetic properties. At least one coil A, the primary winding, is wound on the cores, which are thereby electrically coupled. Hence, both cores SK and RK are traversed by the same magnetic flux. As a result of their different magnetic properties, different magnetic fields are generated in the two cores SK and RK. A coil B is wound on the source core SK and a second coil is wound on the regulating core RK. Coils B and C are secondary windings and are designed to be connected in an additive or subtractive series circuit, depending on the desired variation in secondary voltage, or to be arranged in open circuit.
    Type: Grant
    Filed: August 6, 1992
    Date of Patent: June 6, 1995
    Assignee: Susanne Riedi-Joks
    Inventor: Hanspeter Bitterli
  • Patent number: 5418513
    Abstract: A transformer core assembly in a transformer comprises a coil having a primary winding and a secondary winding which are successively wound about a hollow coil bobbin, in division, with respect to a longitudinal direction of the hollow coil bobbin, and a pair of E-type cores in which central core sections of respective three core sections extending in parallel relation to each other are inserted respectively from both ends of the coil bobbin into a hollow section therewithin. The core sections of one of the pair of E-type cores have lengths thereof which are formed shorter than lengths of the core sections of the other E-type core. When the central core sections are inserted respectively into the hollow section within the coil bobbin, so-called core gaps defined such that the core sections have respective forward ends thereof which are abutted against each other are located within an area corresponding to the primary winding of the coil bobbin.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: May 23, 1995
    Assignee: Stanley Electric Co. Ltd.
    Inventors: Shigeo Fujisawa, Kazuhiko Marumo, Takashi Moribayashi
  • Patent number: 5416459
    Abstract: An engine igniting coil device wherein an I-type core fitted in a hollow portion of a primary coil bobbin and a U-type core are arranged to oppose at their end faces, each other at a specified gap therebetween to form a closed magnetic circuit. The primary coil bobbin with the I-type core has a core holding portion integrally formed thereon for attaching thereto an end portion of the U-type core and the core holding portion also serves as an anti-cracking cover. This cover can accurately determine the positions of both cores and can effectively prevent initiation of cracking in the potting resin injected and cured in the coil case.
    Type: Grant
    Filed: September 20, 1993
    Date of Patent: May 16, 1995
    Assignee: Toyo Denso Kabushiki Kaisha
    Inventors: Yasuhiko Ida, Makoto Sakamaki
  • Patent number: 5414401
    Abstract: A multi-pole magnetic component, such as an inductor, includes z-folded conductive film windings and a core having a plurality of pairs of spaced apart core posts extending between a base plate and a top plate of the core. The core includes an air gap that is distributed substantially evenly along the flux path. Magnetic flux flows through the core posts in a series manner so as to have an opposite flux direction in adjacent poles. Preferably, the air gap is determined such that the ratio of the distance between each adjacent core post and the distance between the base and top plates results in magnetic fields that are substantially tangential to the surface of the conductive film winding. Furthermore, the core posts are preferably shaped to have a larger cross sectional area at the base portion of the posts than at the top portion thereof. Alternatively, the core posts are attached to the bottom plate and are inserted into suitably shaped cut-out portions of the top plate.
    Type: Grant
    Filed: February 20, 1992
    Date of Patent: May 9, 1995
    Assignee: Martin Marietta Corporation
    Inventors: Waseem A. Roshen, Alexander J. Yerman
  • Patent number: 5400005
    Abstract: A transformer or inductor is made by wrapping a magnetic core material about a toroid-like structure made up of one or more electrical windings. A ferroresonant transformer may be constructed by including a slotted washer between primary and secondary windings. By shorting one of the windings, the ferroresonant transformer can be made into a gapped inductor with the gap totally enclosed within the core.
    Type: Grant
    Filed: March 22, 1993
    Date of Patent: March 21, 1995
    Assignee: Albar, Incorporated
    Inventor: Howard H. Bobry
  • Patent number: 5382937
    Abstract: A coil device which can accurately maintain the proportion of voltage caused by the change of the current flowing in a coil device, wherein the outside magnetic substance and the coil are fixed during an assembly of the coil device so that inside magnetic substance can be adjustably moved, or the outside magnetic substance and the inside magnetic substance are fixed so that the coil can be adjustably moved, or only the outside magnetic substance is fixed so that the coil and the inside magnetic substance can be adjustably moved therein. In addition, the coil device produces only small errors in inductance and a minimum leakage flux.
    Type: Grant
    Filed: July 30, 1992
    Date of Patent: January 17, 1995
    Assignee: TDK Corporation
    Inventors: Yutaka Saitoh, Shinichirre Stro, Yukiharu Kimoshita
  • Patent number: RE35092
    Abstract: An ignition coil assembly for an internal combustion engine includes at least one first laminated core contained in a housing and having a plurality of first magnetic path connection end faces exposed to the inside of the housing and at least one second laminated core having a plurality of second magnetic path connection end faces each opposing to one of the first magnetic path connection end faces through a thin gap. A primary coil and secondary coil are wound on the second laminated core, and a plurality of soft waterproof layers are formed on inner walls of the housing to cover the first magnetic path connection end faces of the first laminated core.
    Type: Grant
    Filed: August 8, 1990
    Date of Patent: November 21, 1995
    Assignee: Nippondenso Co., Ltd.
    Inventor: Masami Kojima