Core (e.g., Compressed Powder) Patents (Class 336/233)
  • Patent number: 6504464
    Abstract: A choke coil is provided with a coil formed of a conducting wire covered by an insulating coating and wound in a coil shape; a conducting ring provided one on both ends of the coil; and a bar-shaped core formed of ferrite, ceramic, or the like and penetrating the coil. The ring has a prescribed width and has a centerline extending in the axial direction of the core.
    Type: Grant
    Filed: May 11, 2001
    Date of Patent: January 7, 2003
    Inventor: Kunifumi Komiya
  • Patent number: 6483409
    Abstract: A bead inductor with reliable electrical characteristics and which is constructed so as to be easily mass produced includes a substantially rectangular-parallelepiped core. The core includes an axial portion and an outer peripheral portion, and a coil is formed by winding a metal wire around the axial portion. The axial portion includes a central portion and a peripheral portion. A high strength material is used for the central portion. Metal caps are disposed on both ends of the core. The caps and the coil are connected electrically. In addition, the central portion of the axial portion may be a cavity.
    Type: Grant
    Filed: February 22, 1999
    Date of Patent: November 19, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Takashi Shikama, Masami Sugitani, Hisato Oshima
  • Patent number: 6483413
    Abstract: A laminated inductor includes a structure and arrangement that allows a synthetic reaction during baking to proceed without problems occurring during plating. The laminated inductor includes magnetic sheets provided with associated coil conductors thereon and a magnetic sheet having no conductor thereon for covering the inductor. The magnetic sheets are prepared by mixing respective powders primarily including Fe2O3, NiO, ZnO, and CuO. A composition of the powder thus prepared preferably includes about 45 to about 50 mole percent of Fe2O3, about 5 to about 50 mole percent of NiO, about 0.5 to about 30 mole percent of ZnO, and about 4 to about 16 mole percent of CuO. In addition, about 0.1 to less than about 0.5 percent by weight of Bi2O3 having a specific surface area of about 10 m2/g to about 20 m2/g is added to the powder.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: November 19, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Eiichi Maeda, Katsuhisa Imada
  • Publication number: 20020124384
    Abstract: A method for fabricating a permanent magnetic structure in a substrate, the method comprises the steps of providing a substrate with at least one cavity; providing magnetic particles dispersed with a bonding material for forming a bonding compound; filling the cavities with the bonding compound; and curing the compound to form the permanent magnetic structure in the substrate.
    Type: Application
    Filed: March 12, 2001
    Publication date: September 12, 2002
    Applicant: Eastman Kodak Company
    Inventors: Svetlana Reznik, Bryan A. Beaman, Edward P. Furlani
  • Patent number: 6437678
    Abstract: Noise absorbers (11), which comprise two casing halves (16,17) foldable together around a cable and containing ferrite half-rings, are fixed to a cable (13) in that, prior to the closing of the casing halves, the cable is pressed between two parallel fixing edges (34) of a fork-like projection (32) on one casing end wall (21). The two legs (33) of the fork project over the casing parting line (27), but pass in front of the end wall (21) of the second casing half (17). The cable is laterally compressed somewhat by the substantially parallel faxing edges (34), which ensures a reliable longitudinal fixing to the cable, which does not damage the latter, of the noise absorber made relatively heavy by the elements. Assembly is significantly facilitated in that the definitive fixing takes place prior to the closing of the casing halves and following the folding together of the casing halves no elastic bursting force remains, which attempts to force apart said casing halves.
    Type: Grant
    Filed: March 17, 2000
    Date of Patent: August 20, 2002
    Assignee: Wuerth Elektronik GmbH & Co. KG
    Inventor: Oliver Konz
  • Publication number: 20020084882
    Abstract: A dust core is produced by pressure-molding at least a ferromagnetic powder and an insulating material. The dust core has high magnetic permeability representing the direct current superimposition characteristics, has reduced core loss and has increased mechanical strength. The insulating material comprises a methyl-phenyl silicone resin, wherein the amount of a trifunctional methyl-phenyl silicone resin contained in the methyl-phenyl silicone resin is in a range from 20 to 70 mol % of all silicone resins.
    Type: Application
    Filed: May 30, 2001
    Publication date: July 4, 2002
    Inventor: Hideharu Moro
  • Patent number: 6392525
    Abstract: A magnetic element including: a composite magnetic member A containing a metallic magnetic powder in an amount of 50-70 vol. % and a thermosetting resin in an amount of 50-30 vol. %; a magnetic member B that is at least one selected from a ferrite sintered body and a pressed-powder magnetic body of a metallic magnetic powder; and a coil. The magnetic element is characterized in that a magnetic path determined by an arrangement of the coil passes the magnetic member A and the magnetic member B in series and the coil is embedded in the magnetic member A. The present invention also provides a method for manufacturing the magnetic element.
    Type: Grant
    Filed: December 27, 1999
    Date of Patent: May 21, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Junichi Kato, Osamu Inoue, Seiichi Nakatani, Koichi Hirano, Toshiyuki Asahi
  • Publication number: 20020057184
    Abstract: A method of determining disturbances when discharging molten metal from a metallurgical container having an outlet into a receiving container. In the first step of this process, one directly or indirectly detects mechanical vibrations caused by the discharge of molten metal through the outlet. Thereafter, a second property is measured; the second property so measured varies during the discharge of molten metal from the first metallurgical container to the receiving container. Then, one calculates a sensitivity constant based upon the measuring of the second property. Thereafter, a comparison is made between the vibrations detected by the measuring device with a desired vibrational characteristic, wherein the desired vibrational characteristic is defined in part by the sensitivity constant; the comparison is analyzed to determine the existence of the disturbances within the outlet, and actions are then taken to cause the disturbance(s) to cease.
    Type: Application
    Filed: March 9, 2001
    Publication date: May 16, 2002
    Inventors: Alex Davidkhanian, Frank L. Kemeny, Ali Langari, David I. Walker
  • Patent number: 6380832
    Abstract: An electromagnetic actuator for an automotive internal combustion engine is provided which has a stator, the weight of which is reduced. The electromagnetic actuator has a pair of electromagnets each made up of a stator and a coil, an armature disposed between the pair of electromagnets so as to be reciprocable therebetween, and a first stem provided on one side of the armature for transmitting the movement of the armature to external. The stator is formed by powder molding.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: April 30, 2002
    Assignee: Itami Works of Sumitomo Electric Industries, Ltd.
    Inventors: Hitoshi Oyama, Takao Nishioka, Kenji Matsunuma, Takatoshi Takikawa
  • Patent number: 6369681
    Abstract: A mini transformer comprises a coil, a core, and pins with one ends embedded in plastic pegs at primary winding and plastic pegs at secondary winding respectively. Plastic pegs are provided at the bottom of core. Conductors are electrically connected between pins and coil by soldering. Insulated flanges are provided on both sides of core at the junctions between plastic pegs and core. This can increase the electrical paths from pins to core. Further, it complies with insulation regulations.
    Type: Grant
    Filed: July 28, 2000
    Date of Patent: April 9, 2002
    Inventor: Rex Lin
  • Patent number: 6344781
    Abstract: An electrically conductive wire wound into a conical coil 1 with leads from the small and large ends of the coil. The coil is filled with fine-grained magnetic material 11, and is mounted in a thin-walled, electrically non-conductive carrier 21 designed for precise automated assembly onto a circuit board 15. The wire leads are plastic-welded onto the carrier, and no metallic pads are used, greatly increasing the effective bandwidth of the choke. The small end 4 of the coil is positioned precisely on a micro-strip 17 on the circuit board. Attachment of the wire lead from the small end of the coil to the microstrip is done with minimum lead length and minimum conductive material for the highest possible frequency response. Precise coil positioning, minimal lead length, and a totally non-conductive carrier virtually eliminates electrical reflections and resonances to yield a broadband choke with exceptional frequency range.
    Type: Grant
    Filed: April 14, 2001
    Date of Patent: February 5, 2002
    Inventor: Stephen Amram Slenker
  • Patent number: 6338900
    Abstract: A soft magnetic composite material obtained by dispersing a powdered magnetic material (A) composed of soft ferrite in a polymer (B), wherein the powdered magnetic material (A) is a powdered magnetic material of a random form obtained by grinding a sintered magnetic material, and the average particle size (d2) of the powdered magnetic material (A) is greater than the average crystal grain size (d1) of the sintered magnetic material by at least twice.
    Type: Grant
    Filed: August 24, 1999
    Date of Patent: January 15, 2002
    Assignee: Kureha Kagaku Kogyo K.K.
    Inventors: Masahito Tada, Keiichiro Suzuki
  • Publication number: 20020003383
    Abstract: The present invention pertains to methods for altering the magnetic properties of materials and the novel materials produced by these methods. The methods of this invention concern the application of high voltage, high frequency sparks to the surface of materials in order to alter the magnetic properties of the materials. Specially, the present invention can be applied to diamagnetic silicon to produce ferromagnetic spark-processed silicon.
    Type: Application
    Filed: June 1, 2001
    Publication date: January 10, 2002
    Inventors: Jonathan A. Hack, Rolf E. Hummel, Matthias H. Ludwig
  • Patent number: 6292081
    Abstract: A surface mount, tunable inductor (200) includes a core (205) that is substantially toroidal in shape. The core (205) has a first flattened surface (206) and a second flattened surface (207) opposite the first flattened surface (206), and a hole (208) is formed through the core (205). A wire (210) is wound about the core (205) and terminates in first and second leads (215). The inductor (200) also includes a substrate (220) on which first and second conductive pads (225) are formed. Each of the wire leads (215) is electrically coupled to one of the conductive pads (225), and an adhesive (240) secures the first flattened surface (207) of the core (205) to the substrate (220).
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: September 18, 2001
    Assignee: Scientific-Atlanta, Inc.
    Inventors: James Martin Armfield, Kevin James Frasier
  • Publication number: 20010016977
    Abstract: The invention provides a process for producing a coil-embedded dust core by embedding a coil in magnetic powders comprising ferromagnetic metal particles coated with an insulating material. At the first compression molding step one portion of magnetic powders is filled in a molding die and then compression molded to form a lower core. At a coil positioning step the coil is positioned on the upper surface of the lower core in the molding die. At a coil embedding step another portion of magnetic powders is again filled in the molding die in such a way that the coil is embedded in these magnetic powders. At the second compression molding step pressure is applied to the lower core and coil in the direction of lamination thereof.
    Type: Application
    Filed: January 5, 2001
    Publication date: August 30, 2001
    Applicant: TDK CORPORATION
    Inventors: Hideharu Moro, Tsuneo Suzuki, Tsutomu Chou, Jyunetsu Tamura, Sadaki Sato
  • Patent number: 6268786
    Abstract: The magnetic core of an inductive device is formed of a plurality of wires that extend through the inductive device, and beyond the electric windings. The ends of the wires are formed around the electric windings, meet, and are connected together enveloping the magnetic core and windings forming a complete magnetic circuit. The inductive device may be a transformer with two or more windings, a choke coil with only one winding, or other inductive device. The electric windings may be wound directly onto the wire magnetic core, or may be formed separately and then placed on the magnetic core. A mounting post or the like may be bound into the core and used as a mount for the inductive device; and, cooling tubes and/or large rods for support may be incorporated into the core.
    Type: Grant
    Filed: May 10, 1999
    Date of Patent: July 31, 2001
    Inventor: Harrie R. Buswell
  • Patent number: 6251299
    Abstract: Magnetic material has a ceramics having a composition in the range of Fe2O3 35.0 to 44.5 mol %, NiO 47.0 to 56.5 mol % and CuO 5.0 to 12.0 mol %, and the ceramics having relative magnetic permeability of 15 or less, and composes the inductance element comprising this magnetic material and the internal metallic conductor. For making laminated inductance elements by concurrently baking ceramic green sheets and internal metallic conductors, substances to be used as ceramic green sheets, which substances have the composition in the above mentioned range are used, and a silver or silver alloys are used as the internal metallic conductor, and the calcination is carried out at temperature of 880 to 920° C.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: June 26, 2001
    Assignee: TDK Corporation
    Inventors: Takashi Ito, Yukio Takahashi, Fumio Uchikoba
  • Patent number: 6239681
    Abstract: The core for an induction coil is formed of a plurality of parallel wires that extend through the induction coil, and beyond the coil. The ends of the wires are formed around the induction coil, and the ends of the wires meet and are connected to form a complete magnetic circuit. The induction coil may be a transformer with two or more windings, or a choke coil with only one winding, or other induction coil. The electric winding may be wound directly onto the wire core, or may be formed separately and then placed on the core. A stud or the like may be bound into the core and used as a mount for the induction coil; and, cooling tubes and large rods for support may be incorporated into the core.
    Type: Grant
    Filed: November 30, 1998
    Date of Patent: May 29, 2001
    Inventor: Harrie R. Buswell
  • Patent number: 6236289
    Abstract: A thin electrically conductive wire wound into a conical coil 1 with leads from the small and large ends of the coil. The coil is filled with powdered iron 11, and is mounted in a thin-walled, completely non-conductive, leadless carrier 21 for ease of assembly onto a circuit board 15. The small end 4 of the coil is positioned precisely on a micro-strip 17 on the circuit board to provide maximum bandwidth. The coil is held by the carrier at an angle such that the large end of the coil is displaced from the circuit board by a distance D of at least half the radius of the large end of the coil. Attachment of the leads from the small and large ends of the coil to respective contacts on the circuit board is done with minimum lead length, minimum conductive material, and without the use of metallic pads on the carrier, to yield the highest possible frequency response.
    Type: Grant
    Filed: September 14, 2000
    Date of Patent: May 22, 2001
    Inventor: Stephen Amram Slenker
  • Patent number: 6217790
    Abstract: A BALUN transformer core material contains a Z-type hexagonal system ferrite having an in-plane anisotropy and a high magnetic permeability and such a high resonance frequency as to be in excess of a Snake's limiting line, and therefore, in the BALUN transformer core material, the frequency properties of the magnetic permeability are extremely good. A BALUN transformer core obtained by pressing and sintering this BALUN transformer core material has a high initial magnetic permeability and specific resistance. Moreover, a BALUN transformer obtained by applying a winding to the BALUN transformer core is provided with superior properties which are not poorer as compared with a BALUN transformer constituted of a conventional spinel ferrite, and it is a BALUN transformer having high properties which can be used in a high-frequency band of 300 MHz or more.
    Type: Grant
    Filed: January 10, 2000
    Date of Patent: April 17, 2001
    Assignee: TDK Corporation
    Inventors: Masahiro Onizuka, Kouki Sato
  • Patent number: 6215387
    Abstract: A thick film low value high frequency inductor made by the process of subjecting a conductor layer to a plurality of linear cuts by a pulsing laser cutter imposed simultaneously on the entire length of the linear cut being made to create a cross sectional cut of substantial rectangular configuration. The conductor body is a layer of dried silver thick film ink. The method of making a thick film low value high frequency inductor involves the steps of taking a conductor layer comprised of a dried layer of photo sensitive silver ink, masking the ink with the negative of the desired configuration of the ink, exposing the ink to UV radiation, developing the ink, and firing the layer to adhere the silver to the layer.
    Type: Grant
    Filed: May 18, 1998
    Date of Patent: April 10, 2001
    Assignee: Vishay Dale Electronics, Inc.
    Inventors: Herman R. Person, Thomas L. Veik, Jeffrey T. Adelman
  • Patent number: 6189204
    Abstract: A method for manufacturing a bead inductor includes the steps of forming a molded body of a resin material or a rubber material including a powdered magnetic substance, including a conductor coil defined by a wound, coated metallic wire embedded in the molded body; cutting both end portions of the molded body so as to expose end portions of the conductor coil; and attaching external terminals to the exposed end portions of the conductor coil so that the conductor coil is electrically connected to the external terminals. In order to increase the reliability of connection between the conductor coil and external terminals, both end portions of the conductor coil are immersed into a solder bath, prior to the molded body forming step, so as to include in the solder bath cutting regions of both end portions of the molded body therein such that soldered portions are formed by removing insulation coating on both end portions of the conductor coil.
    Type: Grant
    Filed: June 18, 1999
    Date of Patent: February 20, 2001
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Takashi Shikama, Masami Sugitani, Hisato Oshima
  • Patent number: 6183659
    Abstract: A ferrite oxide magnetic material containing, as basic composition, 11 to 19 mol % of iron oxide calculated in terms of Fe2O3, 11 to 25 mol % of zinc oxide calculated in terms of ZnO, 0 to 10 mol % of copper oxide calculated in terms of CuO, and a residual part of nickel oxide, and further containing, as components subsidiary to the basic composition, 0.01 to 15 wt % of lead oxide calculated in terms of PbO, and 0.01 to 15 wt % of silicon oxide and/or talc calculated in terms of SiO2, wherein the ferrite oxide magnetic material has an initial magnetic permeability of not higher than 8, a sintered density of not lower than 4.8 g/cm3 and a stress-resisting and magnetic-field-resisting characteristic in a range of ±5% calculated in terms of the rate &Dgr;L/L of the change of inductance due to the condition of a magnetic field of 1000 G under a compressive stress P=5 (kg/mm2) parallel with a direction of magnetization.
    Type: Grant
    Filed: October 6, 1999
    Date of Patent: February 6, 2001
    Assignee: TDK Corporation
    Inventors: Satoshi Murayama, Motoi Kumagai
  • Patent number: 6147582
    Abstract: A method of forming a three-dimensional micro-coil on a substrate (10) is provided which consists of forming a first metal layer (14) on the substrate (10). The first metal layer (14) is partitioned into a first plurality of metal strips (16). A sacrificial layer (18) is formed on the first plurality of metal strips (16). A second metal layer (24) is formed on the sacrificial layer (18). The second metal layer (24) is then partitioned into a second plurality of metal strips (26) such that a continuous loop of metal is formed between the first plurality of metal strips (16) and the second plurality of metal strips (26). This continuous loop of metal defines windings for a three-dimensional micro-coil (28) with one side in contact with the substrate (10).
    Type: Grant
    Filed: March 4, 1999
    Date of Patent: November 14, 2000
    Assignee: Raytheon Company
    Inventors: Charles L. Goldsmith, Andrew Malczewski, John C. Ehmke, Zhimin Yao
  • Patent number: 6140902
    Abstract: A thin magnetic element which comprises a coil pattern formed on at least one side of a substrate and a thin magnetic film formed on the coil pattern, wherein:said thin magnetic film is for++med to a thickness of 0.5 .mu.m or greater but 8 .mu.m or smaller;and at least one of the following conditions, that is, assuming that the thickness and width of a coil conductor constituting the coil pattern are t and a, respectively, an aspect ratio t/a of the coil conductor satisfies the following relationship: 0.035.ltoreq.t/a.ltoreq.0.35;and assuming that the width of the conductor constituting the coil pattern is a and the distance between the mutually adjacent coil conductors in the coil pattern is b, the following relationship: 0.2.ltoreq.a/(a+b) is satisfied.
    Type: Grant
    Filed: July 31, 1997
    Date of Patent: October 31, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kiyohito Yamasawa, Yasuo Hayakawa, Takashi Hatanai, Akihiro Makino, Yutaka Naito, Naoya Hasegawa
  • Patent number: 6137389
    Abstract: The present invention is directed to an inductor element for noise suppression capable of suppressing the high frequency component in the GHz band through absorption.A core for passing through a signal line conductor is provided. The core is at least partially constituted with a compound member that is prepared by mixing ferromagnetic metal particles and resin. The compound member imparts a frequency-dependant absorption loss to a signal running through the signal line conductor. The absorption loss starts essentially in the GHz band and the high level of absorption remains in effect up to at least 20 GHz.
    Type: Grant
    Filed: September 11, 1996
    Date of Patent: October 24, 2000
    Assignee: TDK Corporation
    Inventor: Fumio Uchikoba
  • Patent number: 6137393
    Abstract: A power cord transformer includes a core of ferromagnetic material, a primary coil and a secondary coil both provided around the core. The core and coils have such a shape that the distance between two points on the primary coil and also the distance between two points on the secondary coil is always smaller than twice the largest axis of the power cord cross-section.
    Type: Grant
    Filed: July 21, 1999
    Date of Patent: October 24, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Argus F. C. Doss Desouza, Pieter J. M. Smidt, Pieter J. Van Der Zaag, Martinus A. M. Gijs, Gerjan F. A. Van De Walle
  • Patent number: 6120916
    Abstract: A composite magnetic material showing reduced losses and reduced permeability when it is subjected to a magnetic field at frequencies below approximately 100 MHz. It comprises magnetic particles in the form of wafers dispersed in a dielectric binder. The polycrystalline magnetic ceramic wafers are oriented so that their main faces are substantially parallel to the magnetic field.Application especially to cores of inductors or transformers.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: September 19, 2000
    Assignee: Thomson-CSF
    Inventors: Jean-Pierre Delvinquier, Richard Lebourgeois, Michel Pate, Claude Rohart
  • Patent number: 6114940
    Abstract: There is disclosed a BALUN transformer core material which has no magnetic permeability, contains a non-magnetic material and is not influenced by the frequency property of the magnetic permeability even in a high-frequency band. A BALUN transformer core which is obtained by pressing and sintering the BALUN transformer core material has no magnetic permeability and has a high specific resistance. A BALUN transformer which is obtained by applying a winding to the BALUN transformer core is a high-property BALUN transformer which can be operated in a high-frequency band of 600 MHz or more.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: September 5, 2000
    Assignee: TDK Corporation
    Inventors: Sei Kakinuma, Kouki Sato, Masahiro Onizuka, Ko Ito
  • Patent number: 6094109
    Abstract: A power takeoff inductor is an inductor comprised of a hybrid core. Materials with varying low and high permeabilities are combined to create a common hybrid core for the inductor. The inductor can be used in power transmission systems where signals of lower frequencies are transmitted along the same conductors with signals extending across a broad range of higher frequencies. The inductor is used to extract signals having low frequencies without degrading other high frequency signals.
    Type: Grant
    Filed: October 7, 1997
    Date of Patent: July 25, 2000
    Assignee: ADC Telecommunications, Inc.
    Inventors: Clarke V. Greene, Leonel Espirito Santo
  • Patent number: 6087921
    Abstract: A monolithic inductor comprises an elongated substrate having opposite distal ends and, each end having an end cap extending radially from the respective end to support the substrate in spaced relation from a PC board, each end cap having a plurality of intersecting planar surfaces defining corners, an electrically conductive layer forming a winding on the substrate and extending between the opposite ends to provide a winding, and an electrically conductive soldering pad extending partially around at least some of the corners of said end caps at each end of the substrate in electrical contact with the conductive layer, each soldering pad providing a terminal on each of the intersecting planar surfaces.
    Type: Grant
    Filed: October 6, 1998
    Date of Patent: July 11, 2000
    Assignee: Pulse Engineering, Inc.
    Inventor: Timothy Morrison
  • Patent number: 6077453
    Abstract: Provided are an Mn--Zn ferrite in which the core loss is low and Bs is high at high temperatures; a transformer capable of being small-sized and suitable to use at high temperatures; and a method for efficiently driving the transformer. Also provided is a transformer capable of being small-sized and suitable to use in a broad temperature range including high temperatures. Further provided are a high-efficiency transformer capable of being small-sized, in which the core loss in the ferrite core is low and the saturation magnetic flux density is high therein at the temperature at which the transformer is driven; and a high-efficiency driving method for the transformer. Depending on its use, Mn--Zn ferrite to be the ferrite core for the transformers comprises, as the essential components, specific amounts of Fe.sub.2 O.sub.3, ZnO and MnO, and, as the side components, specific amounts of SiO.sub.2, CaCO.sub.3, Nb.sub.2 O.sub.5 and ZrO.sub.2. The core of the transformers is made of the Mn--Zn ferrite.
    Type: Grant
    Filed: January 15, 1999
    Date of Patent: June 20, 2000
    Assignee: TDK Corporation
    Inventors: Hitoshi Saita, Tomofumi Kuroda, Shigeo Okamoto, Naoyoshi Sato
  • Patent number: 6076253
    Abstract: A chip inductor has a coiled conducting wire and a magnetic core which is formed by sintering and in which the coiled conducting wire is embedded. Both end portions of the coiled conducting wire are exposed to both end surfaces of the magnetic core in an arcuate or similar shape. External electrodes are coated on both the end surfaces of the magnetic core and are connected to both end portions of the coiled conducting wire.
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: June 20, 2000
    Assignee: Taiyo Yuden Kabushiki Kaisha
    Inventors: Manabu Takayama, Makoto Saito
  • Patent number: 6071430
    Abstract: Disclosed is a ferrite material having low magnetic losses at frequencies of about 1 megahertz to 100 megahertz, and having firing and sintering temperatures lower than about 1000.degree. C. The material is a nickel-zinc-copper material with cobalt substitution, particularly well suited to the making of magnetic cores and more specifically to the making of micro-inductors.
    Type: Grant
    Filed: March 28, 1997
    Date of Patent: June 6, 2000
    Assignee: Thomson-CSF
    Inventors: Richard Lebourgeois, Adele Le Fur, Claude Rohart
  • Patent number: 6060976
    Abstract: A plane transformer has both a primary plane coil and secondary plane coils fitted in a fitting groove formed on a substrate composed of a magnetic substance. At least either of the primary plane coil and the secondary plane coils is separated into two, so that an output voltage is variably controlled by changing the numbers of turns of the primary and secondary plane coils. The plane transformer can be small in size and thickness, reduces generated heat, and hardly emits electromagnetic noises.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: May 9, 2000
    Assignees: Alps Electric Co., Ltd., Takashi Yamaguchi, Ichiro Sasada
    Inventors: Takashi Yamaguchi, Ichiro Sasada
  • Patent number: 6033593
    Abstract: A BALUN transformer core material contains a Z-type hexagonal system ferrite having an in-plane anisotropy and a high magnetic permeability and such a high resonance frequency as to be in excess of a Snake's limiting line, and therefore, in the BALUN transformer core material, the frequency properties of the magnetic permeability are extremely good. A BALUN transformer core obtained by pressing and sintering this BALUN transformer core material has a high initial magnetic permeability and specific resistance. Moreover, a BALUN transformer obtained by applying a winding to the BALUN transformer core is provided with superior properties which are not poorer as compared with a BALUN transformer constituted of a conventional spinel ferrite, and it is a BALUN transformer having high properties which can be used in a high-frequency band of 300 MHz or more.
    Type: Grant
    Filed: June 10, 1998
    Date of Patent: March 7, 2000
    Assignee: TDK Corporation
    Inventors: Masahiro Onizuka, Kouki Sato
  • Patent number: 6033594
    Abstract: A ferrite which has a high initial permeability, excellent anti-stress properties and excellent temperature characteristic, obviates the use of lead, and is inexpensive, the ferrite being capable of materialize the narrow tolerance and high reliability of a resin mold type inductor without causing environmental pollution, the ferrite having a main component containing at least iron oxide and nickel oxide, an additive containing at least one of bismuth oxide, vanadium oxide, phosphorus oxide and boron oxide, a first auxiliary component containing silicon oxide and a second auxiliary component containing at least one of magnesium oxide, calcium oxide, barium oxide and strontium oxide, the content of the additive being 0.5 to 15 wt % based on the main component, the content of each auxiliary component being 0.1 to 10.0 wt % based on the main component, and a resin mold type inductor for which the above ferrite is applied.
    Type: Grant
    Filed: July 9, 1998
    Date of Patent: March 7, 2000
    Assignee: TDK Corporation
    Inventors: Yasushi Enokido, Ryo Yokoyama, Hitoshi Saita, Naoyoshi Sato
  • Patent number: 5966065
    Abstract: A core for inductance elements is formed of a sintered body of .alpha.-ferric oxide. The core has a flexural strength of at least 6 kgf/mm.sup.2 as measured by a three-point bending method, a specific resistance of at least 10.sup.6 .OMEGA..multidot.cm, a Vickers hardness of 800 to 1,500, and an iron content of 75 to 99.9 wt %, calculated as Fe.sub.2 O.sub.3. The core is produced by granulating, and forming a ferric iron powder, and holding a formed body for sintering at 950 to 1,500.degree. C. for 5 min. to 5 hours in an atmospheric environment.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: October 12, 1999
    Assignee: TDK Corporation
    Inventors: Masahiro Onizuka, Koh Itoh, Sei Kakinuma
  • Patent number: 5959523
    Abstract: Magnetic core structure of the stacked type having outer legs, at least one inner leg, and top and bottom yokes formed of a plurality of stacked groups of layers of metallic laminations. The yoke and leg laminations have their ends cut diagonally to provide a closed magnetic circuit having diagonal joints between adjoining ends of the yoke and leg laminations. The length dimensions of the inner leg laminations are uniform from layer to layer within each group, while the junction of the diagonally cut ends of the inner leg laminations are offset from the centerline thereof from layer to layer in a step pattern that progresses an equal number of steps on each side of the centerline of each group of layers of inner leg laminations to be step dependent. The configuration of the outer leg laminations and the top and bottom yoke laminations are uniform from layer to layer within each group to be step independent.
    Type: Grant
    Filed: October 15, 1996
    Date of Patent: September 28, 1999
    Assignee: ABB Power T&D Company Inc.
    Inventor: Johan Westberg
  • Patent number: 5916476
    Abstract: To an oxide magnetic material consisting essentially of, calculated as oxides, 15-30 mol % of Fe.sub.2 O.sub.3, 6-12 mol % of CuO, and 58-79 mol % of NiO as main ingredients, 1.5-4.5% by weight of PbO, 1.0-3.7% by weight of SiO.sub.2, 0.7-1.0% by weight of CoO, and 0.01-1.0% by weight of ZnO are added as additives. The material is suited to form magnetic cores for operation in high-frequency bands.
    Type: Grant
    Filed: March 26, 1998
    Date of Patent: June 29, 1999
    Assignee: TDK Corporation
    Inventors: Tatsuya Shimazaki, Yutaka Saito
  • Patent number: 5906768
    Abstract: A ferrite core of the invention is useful for reducing the power loss of Ni--Cu--Zn ferrites, and so for particle accelerators, and power transformers. This core comprises a ferrite magnetic material containing as major components 47 to 50 mol % of iron oxide calculated as Fe.sub.2 O.sub.3, 10 to 25 mol % of nickel oxide calculated as NiO, 2 to 15 mol % of copper oxide calculated as CuO and 15 to 35 mol % of zinc oxide calculated as ZnO, and further containing as subordinate components 0.05 to 1.5 wt % of cobalt oxide calculated as CoO, 0.05 to 0.8 wt % of tungsten oxide calculated as WO.sub.3 and 0.03 to 0.5 wt % of bismuth oxide calculated as Bi.sub.2 O.sub.3, all based on the major components. Consequently, there is achieved a ferrite core having a power loss at 100.degree. C. of up to 210 kW/m.sup.3, and a power loss at 25.degree. C. of up to 140 kW/m.sup.3, as measured at f.multidot.Bm product=25 kTHz (f=1 to 10 MHz).
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: May 25, 1999
    Assignee: TDK Corporation
    Inventors: Sei Kakinuma, Yutaka Saito, Kensuke Ara
  • Patent number: 5896079
    Abstract: Common mode ferrite bead is provided for suppressing EMI/RFI. The bead includes a ferrite body of substantially rectangular configuration with top and bottom surfaces, first and second end surfaces and first and second side surfaces. Six apertures pass entirely through the body from the first end surface to the second end surface. Grooves may be provided in bottom surface. Two conductors are provided through the body such that each of the conductors passes through each of three of the apertures through the body. The opposed ends of the conductors are bent to fit in the grooves in the bottom surface of the body. These ends of the respective conductors define contact which can be soldered to conductive pads on a circuit board.
    Type: Grant
    Filed: June 24, 1997
    Date of Patent: April 20, 1999
    Assignee: Fair-Rite Products Corporation
    Inventor: Richard G. Parker
  • Patent number: 5896078
    Abstract: A soft magnetic alloy thin film includes a fine crystalline phase and an amorphous phase. The fine crystalline phase includes an average crystalline grain size of 10 nm or less in diameter and has body-centered cubic structure mainly composed of Fe. The amorphous phase has a nitrogen (N) compound as the main composition and occupies at least 50% of the structure of the thin film. An element M is incorporated at least in the amorphous phase, and includes at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, W, and rare earth metal elements. A plane-type magnetic device is made using this thin film.
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: April 20, 1999
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yasuo Hayakawa, Akihiro Makino
  • Patent number: 5871662
    Abstract: The invention describes a transformer core of NiZn ferrite material. Said transformer core exhibits low overall losses when it is used in a transformer. Said low losses are attained if the majority of the grains of the sintered ferrite material have a monodomain structure. This is the case if the average grain size is smaller than 2.8 microns. The average grain size of the sintered material preferably ranges of from 1.3 to 2.6 microns. The .delta.-value is preferably less than 4 nm.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: February 16, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Pieter J. Van Der Zaag, Arjan Noordermeer, Pieter J. Van Der Valk
  • Patent number: 5850682
    Abstract: In a chip type common mode choke coil, a plurality of non-magnetic sheets on which conductor lines are formed are laminated one on another to form a non-magnetic member, and the conductor lines are connected to form primary and secondary coils inside the non-magnetic member, and a pair of magnetic layers are formed on the upper and lower surface of the non-magnetic member, and magnetic cores are arranged substantially at the centers of the loops of the coils in such a manner that they penetrate the non-magnetic member and are connected to the pair of magnetic layers, whereby a closed magnetic path crossing the primary and secondary coils is formed.
    Type: Grant
    Filed: July 9, 1996
    Date of Patent: December 22, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Tomoaki Ushiro
  • Patent number: 5847947
    Abstract: The structure of a high voltage transformer is disclosed. The transformer structure has a magnetic core, a multi-layer printed circuit board (PCB), a conductor winding, a voltage doubling rectifier means, a magnetic means, a supporting means, and insulated oil. The multi-layer PCB has spiral coils used as a secondary winding. A conductor windings is used as a primary winding. The voltage doubling rectifier means includes an anode voltage doubling rectifier circuit and a cathode voltage doubling rectifier circuit which are respectively formed on a first and a second insulated boards. The two voltage doubling rectifier is used to increase the voltage gain. The magnetic means has a top magnetic cap and a bottom magnetic cap. The mullet-layer PCB and the voltage doubling rectifier means are interposed between the top and the bottom magnetic cap for decreasing the leakage magnetic flux. The breakdown distance can be maintained in an appropriate distance by using the supporting means.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: December 8, 1998
    Assignee: Industrial Technology Research Institute
    Inventors: Tsung-Ming Pan, Jang-Tzeng Lin, Hui Pin Yang
  • Patent number: 5838215
    Abstract: A radio frequency (RF) choke inductor (102, 500, 600) includes a magnetic core (502, 602) which substantially dissipates RF and microwave signals. The magnetic core (502, 602) is sufficiently lossy to provide a substantially resistive impedance at RF and microwave frequencies. The magnetic core is formed by providing a homogeneous ferrite composition characterized by a mixture of ferrous ions and ferric ions (404), and then sintering the homogeneous ferrite composition in an inert gas atmosphere (412) to provide a rapid electron exchange reaction. A conductive wire is then wound about the magnetic core (414) to complete the choke inductor.
    Type: Grant
    Filed: February 5, 1996
    Date of Patent: November 17, 1998
    Assignee: Motorola, Inc.
    Inventors: Wang-Chang Albert Gu, E. S. Ramakrishnan, Robert A. Burr, Adam D. Moya
  • Patent number: 5831505
    Abstract: A choke coil equipped with a bobbin which is easy to form, which is resistant to mechanical impacts and which is light in weight and inexpensive. A bobbin 2 is formed, for example, by fitting or gluing together a bobbin member 21 formed of a magnetic substance and a bobbin member 22 formed of a non-magnetic substance. The magnetic substance bobbin member 21 is equipped with a core portion 23a with flange members 24a and 25a at the ends thereof and a flange member 26a provided in the central section thereof. The non-magnetic substance bobbin member 22 is equipped with a tubular portion 23b with flange members 24b and 25b provided at the ends thereof and a flange member 26b provided in the central section thereof. A tubular body portion 23 of the bobbin 2 is formed by the core portion 23a and the tubular portion 23b, and flange portions 24, 25 and 26 of the bobbin 2 are respectively formed by flange members 24a/24b, 25a/25b and 26a/26b.
    Type: Grant
    Filed: September 2, 1997
    Date of Patent: November 3, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Koichi Yamaguchi, Toshi Numata
  • Patent number: 5825272
    Abstract: A choke coil is disclosed which exhibits sufficient capability in suppressing both common-mode noise and normal-mode noise with a small number of parts. A bobbin is formed of a rod and flanges provided for the rod. A pair of windings are reeled around the rod. Further, one side of a hollow-rectangular integral-type magnetic core is inserted into a hole formed in the rod of the bobbin. The heights of the flange of the bobbin are set as L2 in the upward direction, while the heights of the flange of the bobbin are determined as L1 in the downward direction (as illustrated) with L1>L2, i.e., the heights of the flange are varied in the directions along the outer peripheral surfaces of the flange.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: October 20, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Tatsuyuki Yamada, Kouichi Yamaguchi, Takaaki Ooi
  • 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