Smoothing Type (e.g., Direct Current Power Supply Filters Or Decoupling Filters) Patents (Class 333/181)
  • Patent number: 6183304
    Abstract: The invention relates to electrical devices which include at least one pair of dissimilar metal members with respective surfaces for bringing into contact with each other or with other receptors to establish an electrical connection, and antenna-effect inhibiting means such as a ferrite composition are disposed adjacent to the connection surface of at least one of the contact members. In a form of the invention for use with single wires or a pair of multiple wires, each wire is provided with an individual antenna-effect inhibiting means, such as a ferrite housing, adjacent to a connector thereon.
    Type: Grant
    Filed: November 23, 1998
    Date of Patent: February 6, 2001
    Assignee: Omega Engineering, Inc.
    Inventors: Milton Bernard Hollander, William Earl McKinley, Russell Stewart
  • Patent number: 6181571
    Abstract: A printed-wiring board is incorporated into an electronic device housing constructed of a conductive member, and has a ground pattern. A metal plate having a size equal to or larger than the printed-wiring board is disposed in a position facing to the printed-wiring board. The metal plate has a characteristic impedance corresponding to an electric characteristic and a relative position to the printed-wiring board. A connecting member electrically connects the ground pattern of the printed-wiring board to the metal plate, and includes an impedance element having a value substantially equal to the characteristic impedance between the printed-wiring board and the metal plate. An occurrence of radiant noises caused by standing-waves etc. is thereby prevented.
    Type: Grant
    Filed: March 5, 1999
    Date of Patent: January 30, 2001
    Assignee: Canon Kabushiki Kaisha
    Inventor: Satoshi Sugimoto
  • Patent number: 6137379
    Abstract: A universal noise controller is constructed of two windings on a magnetic core with a potentiometer connected across the windings. The input is connected in parallel to the windings and the potentiometer and the output is taken from a node in the center of the windings and a wiper arm of the potentiometer. This arrangement allows a phase change of 360 degrees by overlaying another signal thus providing phase cancellation from positive 180 degrees to negative 180 degrees thereby providing suitable noise cancellation based on the position of the wiper arm.
    Type: Grant
    Filed: September 23, 1996
    Date of Patent: October 24, 2000
    Inventor: Russell C. Morrill
  • Patent number: 6127903
    Abstract: A filter apparatus includes a housing having a first body portion and a second body portion which mate together to enclose an accessible inner portion of the housing. Filtering elements disposed within the inner portion filter signals transmitted through a pair of signal carriers which pass through the inner portion. A pair of guides disposed within the inner portion maintain the electrical conductors in a predetermined positional relationship with certain of the filter elements. The guides are each actuated by placing a signal carrier against a predetermined portion of the guide and applying manual pressure against the signal carriers to cause the signal carrier to be pressed into a the predetermined positional relationship. Certain embodiments include contact push posts which pierce an insulating layer of a corresponding signal carrier to make electrical contact with the signal carrier. Other embodiments include a cutting element to sever the signal carriers to implement a four-terminal filter.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: October 3, 2000
    Assignee: Broadcom HomeNetworking, Inc.
    Inventor: Peter F. Foley
  • Patent number: 6125044
    Abstract: A printed circuit board (PCB) assembly includes a PCB having and a ferrite attenuator. The PCB includes input/output signal paths for carrying signals to and from the PCB, power paths for conducting power to the PCB, and ground paths for connecting the PCB to a ground level. The ferrite attenuator surrounds the input/output signal paths, the power paths, and the ground paths. The PCB assembly is preferably used in a system, such as a computer system, where the ferrite attenuator suppresses electromagnetic interference (EMI) generated in the system.
    Type: Grant
    Filed: March 23, 1999
    Date of Patent: September 26, 2000
    Assignee: Hewlett-Packard Company
    Inventors: Andrew M. Cherniski, Alisa C. Sandoval
  • Patent number: 6121857
    Abstract: An RF choke for separating or joining an RF signal and an AC power signal on e.g. a CATV transmission line has a large current carrying capacity. The RF choke uses 14 to 16 gauge magnetic wire in order to carry currents as high as 15 amps. In addition, the RF choke has excellent performance as measured by RF frequency response and hum modulation.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: September 19, 2000
    Assignee: Harmonic, Inc
    Inventor: Wei Huang
  • Patent number: 6115264
    Abstract: A multilayer high frequency electronic component having a greatly reduced resistance component of a signal line which functions as an inductor is constructed such that the signal line includes at least two conductor patterns provided on the surface of insulation sheets. The at least two conductor patterns have substantially the same shape and different pattern widths. The at least two conductor patterns are arranged to extend continuously across an insulation layer.
    Type: Grant
    Filed: November 25, 1998
    Date of Patent: September 5, 2000
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Koji Nosaka
  • Patent number: 6097262
    Abstract: A transmission line impedance matching apparatus is disclosed that limits longitudinal signals and matches the longitudinal characteristic impedance between two conductors and comprises a common mode choke and an impedance matching device. The common mode choke, comprising two windings wound in the same direction, acts as a high impedance to longitudinal high frequency signals. As a result of this, standing waves are caused by the metallic signals reflecting off the choke. The impedance matching device, comprising two windings wound in the same direction, provides a good match to the longitudinal characteristic impedance and thus reduces standing longitudinal waves and reflections. The apparatus may include a terminal corrector or a mid-line corrector, or a combination thereof. This invention may allow greater bandwidth to be dedicated to services and allow transmission over longer subscriber loops before the minimum S/N ratio is achieved.
    Type: Grant
    Filed: April 27, 1998
    Date of Patent: August 1, 2000
    Assignee: Nortel Networks Corporation
    Inventor: R. Alan Combellack
  • Patent number: 6094110
    Abstract: This invention relates to a radio frequency ("RF) choke having improved insertion loss and reduced hum modulation. The RF choke includes three conductors wound in series around an elongated core. The first conductor forms a first group of windings where each turn abuts the next turn. The second conductor forms a second group windings where each turn is spaced from the next. The third conductor forms a third group of windings where each turn abuts the next turn. The second and third groups of windings are wound in an opposite direction around the core than the first group of windings. The elongated core can include two separate diameters. A plurality of resistors are electrically connected to said conductors to provide an impedence that effectively blocks an RF signal at between 5 MHz and 1000 MHz. This type of choke can be employed in numerous circuits, including line splitters and couplers, trunk amplifiers, bridge amplifiers and line extender amplifiers.
    Type: Grant
    Filed: November 18, 1998
    Date of Patent: July 25, 2000
    Assignee: National Electronic Devices, Inc.
    Inventor: Prabhakara Reddy
  • 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: 6091310
    Abstract: A laminated multi-layer printed board having at least a power source circuit layer, at least a ground layer and at least a signal layer includes a hole which extends through the board to the power source circuit layer. An inductor is provided in the hole.
    Type: Grant
    Filed: March 26, 1998
    Date of Patent: July 18, 2000
    Assignee: NEC Corporation
    Inventors: Kazuaki Utsumi, Shiro Yoshida, Mitsuo Saitou
  • Patent number: 6075425
    Abstract: A power-line filter for operation with a converter is provided having a regulated voltage source and sinusoidal phase currents, with the power-line filter helping to eliminate interference voltages particularly in the frequency range from 2 kHz to 150 kHz, which are normally not taken into account. The leakage currents to ground, in this context, can be minimized to the point that it is possible to operate the converter in an (AC/DC sensitive) Interference Filter (IF) protective circuit-breaker.
    Type: Grant
    Filed: January 13, 1999
    Date of Patent: June 13, 2000
    Assignee: Siemens Aktiengesellschaft
    Inventors: Kurt Gopfrich, Manfred Karasek
  • Patent number: 6043724
    Abstract: Described is a novel implementation of a medium and high frequency on-module (off-chip)/on-chip power noise filter for power noise sensitive circuits. To achieve this, a second order low-pass approach is used. The first stage capacitor is located on-module (off-chip), and the second stage capacitor is implemented on-chip.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: March 28, 2000
    Assignee: International Business Machines Corporation
    Inventors: Roland Frech, Erich Klink, William F. Shutler, Ulrich Weiss, Thomas-Michael Winkel
  • Patent number: 6016089
    Abstract: A printed circuit device comprising a printed circuit board carrying capacitors connected in use as common mode filters, a casing component supporting the printed circuit board and electrically grounded in use, and, a plurality of electrically conductive resilient contact elements resiliently engaging said casing component so as to make electrical connection thereto, each of said contact elements being physically secured to the printed circuit board and providing a ground path for a respective common mode filtration capacitor.
    Type: Grant
    Filed: December 17, 1997
    Date of Patent: January 18, 2000
    Assignee: Lucas Industries
    Inventor: Stephen John Goudie
  • Patent number: 5994979
    Abstract: A noise filter has a magnetic core having a pair of magnetic core members each with a coupling surface. Each of the magnetic core members has a dented portion so arranged that, when the magnetic core members are closed together on the coupling surfaces, a closed magnetic path and an opening for inserting therethrough a cable are formed between the magnetic core members. An electrically insulating outer sheath member is disposed on an outer surface of each of the pair of magnetic core members. An electrically insulating coating member is disposed on an inner wall surface of each of the dented portions.
    Type: Grant
    Filed: January 27, 1998
    Date of Patent: November 30, 1999
    Assignee: Taiyo Yuden Kabushiki Kaisha
    Inventors: Koji Taketomi, Kiyoshi Tanbo
  • Patent number: 5977713
    Abstract: A high voltage noise filter for use in magnetron devices comprises a coil of a conductive wire coated with an insulating layer and another coil of the conductive wire with a conductive layer formed on the insulating layer, the two coils connected to each other in series A joint portion of the two coils has a triple-layered structure wherein a high withstand voltage layer either of a semiconductive or insulative member is formed in the vicinity of an end portion of the conductive layer, as interposed between the outer peripheral surface of the insulating layer and the conductive layer.
    Type: Grant
    Filed: March 26, 1997
    Date of Patent: November 2, 1999
    Assignee: Matsushita Electronics Corporation
    Inventors: Hiroshi Ochiai, Mitsuichi Hiraishi, Masanori Yoshihara, Yasunobu Nakano
  • Patent number: 5978231
    Abstract: An insulative magnetic layer is disposed between a power source conductor layer and a ground conductor layer of a printed-wiring board. Two pieces of conductors are formed by cutting out a part of the power source conductor layer. Another two pieces of conductors are formed by cutting out a part of the ground conductor layer. The former conductors and the latter conductors are connected by five viaholes. A spiral coil inductor of a spiral form is formed in this way. This inductor has the strengthened inductance owing to the insulative magnetic layer provided therein.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: November 2, 1999
    Assignee: NEC Corporation
    Inventors: Hirokazu Tohya, Shiro Yoshida, Yuzo Shimada
  • Patent number: 5969583
    Abstract: An EMI filter and method of manufacturing thereof is described. The filter includes two or more power conductors and a ground conductor. The power conductors and the ground conductor are separately wound onto a core to form a common-mode choke. The filter may be located in an equipment chassis. Capacitors may be coupled to the choke to improve filter performance. The core may comprise at least two magnetic beads. The core material and number of turns of the conductors may be chose to control the frequency range of common-mode noise rejection. The frequency range may be that in which adequate common-mode noise rejection is achieved for a diagnostic ultrasound machine, e.g., approximately 0 to 20 MHz.
    Type: Grant
    Filed: December 23, 1996
    Date of Patent: October 19, 1999
    Assignee: Acuson Corporation
    Inventor: James B. Hutchison
  • Patent number: 5914644
    Abstract: A printed circuit (PC) board-mountable ferrite electromagnetic interference (EMI) filter (702, 1003, 1003") for PC conductors (701, 1001, 1002) of a printed circuit (PC) board (700, 1000) that accommodates large numbers of PC conductors, and is cost-effective. One embodiment of the EMI filter is used with a PC board (700) that routes PC conductors (701) in a step-function (i.e., a "U"-shaped) pattern. The EMI filter comprises a ferrite body (702) that defines two parallel passageways (708, 709), i.e., has a figure-8 shape in cross section. The portion (710) of the PC board that defines the PC conductor portions extending in the one direction lies in one passageway, whereas the portion (711) of the PC board that defines the PC conductor portions extending in the other direction lies in the other passageway. A different embodiment of the EMI filter is used with a PC board (1000) that routes sets (1001, 1002) of PC conductors in a cross-hatch (i.e.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: June 22, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Galen L. Carter, David A. Norte, Woong K. Yoon
  • Patent number: 5898576
    Abstract: A printed circuit board including a terminated power plane is described. Specifically, the power-ground plane construction includes a dielectric layer, a power plane having a peripheral edge, and a ground plane. The ground plane is spaced from the power plane by the dielectric layer, and is positioned in an opposed relationship to the power plane. The power-ground plane construction also includes a termination element coupling the power plane, at or adjacent the peripheral edge thereof, to the ground plane so as to terminate the power plane. In one embodiment, a plurality of termination elements couple the power plane, at or adjacent the peripheral edge thereof, to the ground plane. The termination elements are spaced from each other at substantially regular intervals. In another embodiment, a termination element is a strip or sheet element coupling continuous lengths of the peripheral edge of the power plane to ground plane.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: April 27, 1999
    Assignee: Bay Networks Inc.
    Inventors: John J. Lockwood, Edward J. Pavlu, III
  • Patent number: 5892668
    Abstract: A noise-cut filter device for a power converter, including at least one noise-cut filter, for filtering switching noise occurring upon a switching operation of a semiconductor switching device of the power converter is disclosed. In this filter device, the noise-cut filter includes first and second planar conductors, and a dielectric sheet having upper and lower surfaces on which the first and second conductors are disposed to face each other through the dielectric sheet. The first and second planar conductors cooperate with the dielectric sheet to form a circuit having both functions of an inductor and a condenser. The current of a main circuit of the power converter flows through the opposite ends of the first planar conductor, while the current based on the switching noise, which flows from the first conductor to the second conductor, is led to ground by the second conductor.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: April 6, 1999
    Assignee: Fuji Electric Company, Ltd.
    Inventors: Kenji Okamoto, Shinji Uchida, Takao Maeda, Takashi Aihara, Yoshihiro Matsumoto, Naoto Fukasawa
  • Patent number: 5844460
    Abstract: Wound, solid state inductors are provided by winding flexible plastic tape having electrically insulative and magnetic permeability properties. Such tape is sometimes referred to as magnetic tape. An electrically conductive layer is placed on at least one surface of the magnetic tape, or both, and electrical connections are provided to the ends of the electrically conductive layer or layers. When the magnetic tape is wound into a coil, spirally or helically, and an alternating current is applied to the electrical connection, an inductive reactance will be noted. If there are two electrically conductive layers, and a voltage is applied between them, a capacitive reactance will be noted. In that case, a complex capacitive inductor element or inductive capacitor element has been configured. The wound inductors are small, light weight, inexpensive, and relatively shock proof, when compared with prior wound inductors having separate magnetic cones and wire windings placed over them.
    Type: Grant
    Filed: June 9, 1997
    Date of Patent: December 1, 1998
    Assignee: Dyalem Concepts Inc.
    Inventors: Alexei Bogdan, Emil S. Sagalovich
  • 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: 5825259
    Abstract: A termination is provided for a differential transmission line such as unshielded twisted pair (UTP) to isolate a connected device from electromagnetic interference present on the UTP in the form of differential mode and common mode noise. An example of an electromagnetic interference isolator comprises a common mode and a differential mode termination, a common mode choke which exhibits substantially constant impedance over a wide bandwidth and a centre tapped isolation transformer.
    Type: Grant
    Filed: March 25, 1997
    Date of Patent: October 20, 1998
    Assignee: Madge Networks Limited
    Inventor: Lewis Freeth Harpham
  • Patent number: 5805042
    Abstract: A radio frequency choke for use in a cable television transmission and distribution circuit is disclosed. The radio frequency choke comprises a core of zinc-ferrite material as provided by MMG/NEOSID, Ltd., part number 31P0250012, and a wire coil wound around the core. The coil includes a first lead, a first clockwise winding of N1 turns around the core, the first lead being connected to an input of the first winding, a second counterclockwise winding of N2 turns around the core, a third counterclockwise winding of N3 turns around the core, and a second lead connected to an output of the fourth winding. In a preferred embodiment, there are six turns in the first clockwise winding, five turns in the second clockwise winding, and five turns in the third counterclockwise winding. Moreover, in the preferred embodiment, resonance damping resistors of approximately 2 K.OMEGA. are connected between the windings of the radio frequency choke.
    Type: Grant
    Filed: March 31, 1997
    Date of Patent: September 8, 1998
    Assignee: Scientific-Atlanta, Inc.
    Inventors: Jack B. Chastain, Sou-Pen Su
  • Patent number: 5805032
    Abstract: In order to avoid filter excitations of subharmonics or intermediate harmonics, that is to say of oscillations in the frequency range between integral harmonics of the mains frequency (f.sub.N), in the case of an attenuation resistor (R1, R3, R3') in parallel with a series resonant circuit comprising a filter inductor (L1, L3) in series with a filter capacitor (C1, C31, C31'), the resistance is dimensioned in such a way that a current gain of the filter (F1-F3) at its frequency pole points with an AC mains (1) is not greater than 6-fold. Double low-pass filters (F1, F2) and high-pass filters (F3) with attenuation resistors (R1, R3, R3') are particularly suitable as filters (F1, F3).
    Type: Grant
    Filed: December 9, 1996
    Date of Patent: September 8, 1998
    Assignee: Asea Brown Boveri AG
    Inventors: Werner Herbst, Thomas Kirsten
  • Patent number: 5801597
    Abstract: A printed circuit (PC) board-mountable ferrite electromagnetic interference (EMI) filter (702, 1003, 1003") for striplines (701, 1001, 1002) of a printed circuit (PC) board (700, 1000) that accommodates large numbers of striplines, and is cost-effective. One embodiment of the EMI filter is used with a PC board (700) that routes striplines (701) in a step-function (i.e., a "U"-shaped) pattern. The EMI filter comprises a ferrite body (702) that defines two parallel passageways (708, 709), i.e., has a figure-8 shape in cross section. The portion (710) of the PC board that defines the stripline portions extending in the one direction lies in one passageway, whereas the portion (711) of the PC board that defines the stripline portions extending in the other direction lies in the other passageway. A different embodiment of the EMI filter is used with a PC board (1000) that routes sets (1001, 1002) of striplines in a cross-hatch (i.e.
    Type: Grant
    Filed: February 5, 1997
    Date of Patent: September 1, 1998
    Assignee: Lucent Technologies Inc.
    Inventors: Galen L. Carter, David A. Norte, Woong K. Yoon
  • Patent number: 5774028
    Abstract: A line filter for a surface mounting device which eliminates noise on a power supply line, and more particularly a line filter for a surface mounting device in which not only a making to mount is easy because a magnitude of the filter is made to be small, but also a noise eliminating characteristic is improved better. The technical construction of the present invention is made such that three capacitor elements are mounted side by side to the capacitor mounting portion formed at top surface of the ferrite core, lead wires are inserted through the lead wire passing through openings among three capacitor elements mounted to the ferrite core, the ground terminal portion is formed by printing to both side surfaces of the ferrite core, and said capacitor, lead wires and ground terminal portion are connected by soldering and then the surface is coated; therefore, there are effects that a surface mounting is easy and a noise eliminating characteristic is excellent.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: June 30, 1998
    Assignee: Samsung Electro-Mechanics
    Inventor: Chang Sik Kim
  • Patent number: 5770984
    Abstract: An EMI filter formed with a U-shaped ferrite core with parallel first and second legs and a center leg surrounded by a grounding and shorting strap and a capacitor connected between the grounding and shorting strap and a portion of a conductor which extends between the first and second legs. Two or more of the filters can be formed as a stacked array. The filter has a substantially improved frequency response over the prior art.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: June 23, 1998
    Assignee: Corcom, Inc.
    Inventors: Michael P. Raleigh, Thomas McCartney
  • Patent number: 5739732
    Abstract: An alternating current (AC) spike absorption circuit employs a pair of back-to back parallel high-speed ultra-soft recovery diodes with unique RFI prevention characteristics. Further high frequency noise suppression is achieved by using a high voltage parallel-connected capacitor and a plurality of series-connected parallel ceramic-type resistors which are formed by resistors having coil windings providing an equivalent circuit of parallel resistance and inductance. The inductance provides ultra high frequency rejection and the resistance provides damping of any ringing oscillation. A surrounding ceramic material casing of the ceramic-type resistors resists the transmission of radio frequency energy.
    Type: Grant
    Filed: January 23, 1996
    Date of Patent: April 14, 1998
    Inventor: Page Huie Man Kit
  • Patent number: 5736910
    Abstract: A modular jack connector mounted on a main printed circuit board and having a receptacle into which a modular plug of an electronic component is inserted. The connector includes a housing, a first set of contacts arranged in the housing each adapted to engage one of the contacts of the plug, a second set of contacts at least partially arranged in the housing and adapted to engaging the main printed circuit board, contact coupling circuit means for electrically coupling the first and second sets of contacts, a capacitor for providing impedance to high frequency noise and interference and a metallic shield at least partially surrounding the housing and connected to a grounding region on the main printed circuit board. In one embodiment, the capacitor is a flexible laminate assembly including first and second conductive sheet members and an intermediate insulative material.
    Type: Grant
    Filed: November 22, 1995
    Date of Patent: April 7, 1998
    Assignee: Stewart Connector Systems, Inc.
    Inventors: Peter K. Townsend, Ted R. Meckley, David Hatch, Don McClune, Robert J. Brennan
  • Patent number: 5726611
    Abstract: An EMC filter for a balanced multi-wired telecommunication line has an oblong closed magnetic path core 50 having at least one first core arm 50a with a first length and second core arms 50b with a second length which is equal to or shorter than the first length, and a plurality of coils 51 constituted by at least one pair of wires. The at least one first core arm 50a and the second core arms 50b constitute a closed magnetic path. The wires of each pair are closely positioned each other and wound around the at least one first core arm 50a so as to produce magnetic fluxes in the first core arm 50a flowing toward the same direction when a common-mode current flows through the wires. Each of the coils 51 has a signal input end and a signal output end, and the wires run in a one-way direction from the signal input ends to the signal output ends, respectively.
    Type: Grant
    Filed: November 18, 1996
    Date of Patent: March 10, 1998
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Kusuo Takagi, Ryoichi Okayasu
  • Patent number: 5719750
    Abstract: A printed board 10 is provided with two ground layers 3a, 3b. These ground layers 3a, 3b are electrically insulated inside the printed board. By connecting circuits with different characteristics (low frequency and high frequency, for example) with the different ground layers 3a, 3b, interference of these circuits caused due to a common ground can be minimized.
    Type: Grant
    Filed: July 2, 1996
    Date of Patent: February 17, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yasushi Iwane
  • Patent number: 5686871
    Abstract: Noise generated in a computer system on a modem adapter card is effectively suppressed by providing an extension to a voltage reference plane. The extension reference plane is coupled to the voltage reference plane of the adapter card by an impedance circuit. The extension reference plane causes the adapter card to have a composite reference plane which has an overall length greater than one-quarter of the wavelength of the signal to be suppressed such that the composite reference plane does not resonate at the frequency of the signal which generated the noise. The reference planes are preferably connected by a resonant circuit so that the two reference planes are effectively electrically connected at high frequencies and are electrically disconnected at low frequencies so that resonance of the boards is also suppressed at the lower frequencies.
    Type: Grant
    Filed: July 12, 1996
    Date of Patent: November 11, 1997
    Assignee: AST Research, Inc.
    Inventor: Jozef B. Baran
  • Patent number: 5619174
    Abstract: A noise filter includes an annular magnetic core made of a soft magnetic alloy ribbon mainly made of Fe and containing B and at least one element selected from a group consisting of Ti, Zr, Hf, Nb, Ta, Mo and W, at least 50% of the soft magnetic alloy structure being composed of body-centered cubic structured fine grains having an average grain size of 30 nm or below, a casing for accommodating the magnetic core and having an insulating plate, a pair of coils separated from each other by the insulating plate, and an electronic circuit for connecting a core element made up of the magnetic core, the casing and the coils.
    Type: Grant
    Filed: July 29, 1994
    Date of Patent: April 8, 1997
    Assignees: Alps Electric Co., Ltd., Research Development Corp. of Japan, Tsuysohi Masumoto
    Inventors: Youichi Kimura, Akihiro Makino, Tsuyoshi Masumoto, Akihisa Inoue
  • Patent number: 5610565
    Abstract: A composite electronic component includes a sintered body, an inductor part and a capacitor part which are formed in the sintered body, and a ground electrode which is formed on an outer surface of the sintered body to be electrically connected to a first capacitor electrode of the capacitor part and not to reach an outer surface of the inductor part on the outer surface of the sintered body.
    Type: Grant
    Filed: February 2, 1995
    Date of Patent: March 11, 1997
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Eiichi Maeda, Katsuhisa Imada, Motoi Nishii, Yoshihiro Nishinaga
  • Patent number: 5604466
    Abstract: An on-chip voltage controlled oscillator for use in an analog phase locked loop receives power from a voltage regulator which greatly reduces the noise seen by the voltage controlled oscillator. The voltage controlled oscillator has a DC bias section which supplies a relatively constant current to the multivibrator to assure a minimum operating frequency. A control signal is used to provide additional current which increases the speed of oscillation. The bias current reduces the transfer characteristics (MHz/volt) of the voltage controlled oscillator making it more immune to noise in the control signal.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: February 18, 1997
    Assignee: International Business Machines Corporation
    Inventors: Daniel M. Dreps, Raymond P. Rizzo
  • Patent number: 5597328
    Abstract: A multi-pole connector for connecting a number of signal lines includes a connector casing and rows of adjacent connecting pins and connecting sockets. At least one planar filter is adjacent one of the rows of the connecting pins or sockets. The at least one planar filter has edge regions producing a ground connection, a connecting site and a number of condensers corresponding to the number of signal lines to be connected. Each of the condensers is assigned to a respective one of the pins or sockets and each has a first coating connected to an associated signal line, a second coating to be connected to ground and a dielectric layer interposed between the first and second coatings. Each of the connecting pins or sockets has a connecting conductor connected to the connecting site. Securing connectors are conductively connected with the connector casing and secure at least one of the edge regions.
    Type: Grant
    Filed: January 13, 1995
    Date of Patent: January 28, 1997
    Assignee: Filtec-Filtertechnologie GmbH
    Inventor: Bob Mouissie
  • Patent number: 5594397
    Abstract: A ground conductor and a signal conductor are provided in an insulating magnetic body respectively. The insulating magnetic body is a compound member that combines ferromagnetic metal particles and an insulating resin. A signal transmission element, a connector or a circuit board with high frequency stopping and low pass characteristics which will ensure reliable absorption of high frequency components in the high frequency range, can be provided.
    Type: Grant
    Filed: March 23, 1995
    Date of Patent: January 14, 1997
    Assignee: TDK Corporation
    Inventors: Fumio Uchikoba, Shigeyuki Nakajima, Takashi Ito, Taro Miura, Makoto Kobayashi, Takahide Kurahashi, Yasushi Iijima
  • Patent number: 5559396
    Abstract: A ballast filter in which the ballast can operate at a total harmonic distortion of power line current of less than 10%. Power dissipated by the filter when at a THD of less than 10% is relatively low. The input impedance of the ballast is chosen to be no greater than twice the equivalent filter impedance of a front end filter and no less than the equivalent filter impedance/1.5. The filter includes a transformer having a core which at times operates within the non-linear region of its B-H curve under nominally rated ballast load conditions.
    Type: Grant
    Filed: October 14, 1994
    Date of Patent: September 24, 1996
    Assignee: Philips Electronics North America Inc.
    Inventors: Gert W. Bruning, Pawel M. Gradzki
  • Patent number: 5554050
    Abstract: An electrical connector assembly includes two mating multiposition electrical connector halves 2, 4 and an insert 10 which is positioned in engagement with the terminals 8 in one of the connector halves. The insert is fabricated from a lead frame 16 which is secured between an insulative substrate 40 and a cover 48. Portions of the lead frame 16 extending into slots 44 and channels 52 on the substrate and cover are punched out to separate connecting tabs 26 from ground buses 18, 20, 22. Surface mount capacitors 38 are soldered to both the solder tab sections 30 on the connecting tabs and to solder contact sections 34 on the ground buses. The insert 10 is then positioned on the terminals 8 on one connector half with the tines 32 in a terminal socket 28 on each connecting tab 26 engaging the terminals 8.
    Type: Grant
    Filed: March 9, 1995
    Date of Patent: September 10, 1996
    Assignee: The Whitaker Corporation
    Inventor: Gary R. Marpoe, Jr.
  • Patent number: 5548165
    Abstract: An apparatus and method for reducing distortion currents present in an alternating current power system supplying power to a load which includes a passive filter and an active filter. In a first embodiment, the passive filter is operably connected to the power system across the load by a switching device. An active filter is then connected across the switching device and operated to draw a current equal to the current through the passive filter. The active filter and the passive filter are thereby connected in series across the load. The active filter is controlled to draw a fundamental frequency component and to provide distortion currents required by the load. In a second embodiment, the active filter is connected in parallel with a first circuit, the parallel combination of which is connected in series with a second circuit across the load.
    Type: Grant
    Filed: July 18, 1994
    Date of Patent: August 20, 1996
    Assignee: Regents of The University of Minnesota
    Inventors: Ned Mohan, Mukul Rastogi
  • Patent number: 5500629
    Abstract: A distributed low-pass filter typically attenuating a signal, 7 db. at 10 MHz., 18 db. at 30 MHz., and continuing at 50 db/decade, without resonant inflections, uses a small, low cost, rectangular tubular bead of outside dimension 3 mm..times.6 mm..times.2 mm., made from a body material having evenly distributed magnetic, dielectric, and resistive properties. A through-conductor completes the distributed filter which acts like a high loss cable transmission line. The tube's inner and outer surfaces are separately coated with an electrode material. The through-conductor electrically connects to the inner electrode, with its ends providing first and second filter terminals, and the outer electrode providing a common, terminal. An a.c. signal impressed between the first and common terminals produces an attenuated signal between the second and common terminals in accordance with the above characteristics. Also, a 6 mm..times.6 mm..times.1 mm block of the body material may typically form a 500 .mu.
    Type: Grant
    Filed: March 2, 1995
    Date of Patent: March 19, 1996
    Inventor: Dennis R. Meyer
  • Patent number: 5495213
    Abstract: The present invention provides an LC noise filter consisting of a capacitance and an inductance, including a first insulation sheet having a plurality of portions folded alternately in the opposite directions and stacked one above another; a first conductor applied to the insulation sheet at one side and adapted to form a coil having a given number of turns when the folded portions of the insulation sheet are folded alternately in the opposite directions and stacked one above another; and a second conductor applied to the insulation sheet at the other side and located substantially opposite to the first conductor to form a capacitance therebetween, whereby the filter can eliminate incoming noises without creation of any undesirable phenomenon such as ringing or the like.
    Type: Grant
    Filed: July 18, 1994
    Date of Patent: February 27, 1996
    Inventor: Takeshi Ikeda
  • Patent number: 5488540
    Abstract: A multi-layered printed circuit board is provided.
    Type: Grant
    Filed: January 18, 1994
    Date of Patent: January 30, 1996
    Assignee: Nippondenso Co., Ltd.
    Inventor: Hironobu Hatta
  • Patent number: 5483136
    Abstract: An improved EMI filter design is provided for an inverter operated dynamoelectric machine. A lossy balun wound choke is connected between a power supply in the form of a bridge rectifier and the inverter. The choke acts as a source resistance. Using the choke as the source resistance, an equiripple approximation to linear phase filter is derived. The filter is placed on the input side of the bridge rectifier. A method of designing an EMI filter for use in conjunction with an inverter operated dynamoelectric machine.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: January 9, 1996
    Assignee: Emerson Electric Co.
    Inventor: Joseph G. Marcinkiewicz
  • Patent number: 5483208
    Abstract: An RF Choke and tap having improved insertion loss, amplitude modulated distortion of video and audio carrier signals at CATV frequencies. The RF choke includes a 20 AWG magnetic wire wound on a ferrite rod. The magnetic field effects of the choke are optimized by selecting the choke winding pattern, rod core material and positioning of a resistor between selected windings. The wire is wound by placing two groups of the 4 tightly wound wires adjacent the ends of the rod. A group of 3 very loosely wound wires is separated from the wound wires and placed between the groups of 4 tightly wound wires. A resistor is electrically connected to a first wire in one of the groups of tightly wound wires and connected to a first wire in the group of the loosely wound wires.
    Type: Grant
    Filed: August 26, 1994
    Date of Patent: January 9, 1996
    Assignee: Scientific-Atlanta, Inc.
    Inventor: Bart F. Spriester
  • Patent number: 5472356
    Abstract: The invention provides a telephone network connector (10, FIG. 8) with a rear portion (47) that holds a cartridge (56) which enables connections directly to ground and through a circuit component to ground. The cartridge lies within an electrically grounded metal shell (32), that, in turn, lies within a molded dielectric container (48). The cartridge has a grounded contact element (74, FIG. 2) which has threaded part (78) extending through a threaded hole (80) in the grounded shell. The cartridge also has a nongrounded contact element (76) which projects through a bushing part (92) of the dielectric container, which isolates the nongrounded contact from the walls of a hole (91) in the metal shell. The molded dielectric container forms a front connect tube (51, FIG. 8) and a pair of side tubes (52, 53).
    Type: Grant
    Filed: October 12, 1994
    Date of Patent: December 5, 1995
    Assignee: ITT Corporation
    Inventor: Herve Bricaud
  • Patent number: 5461351
    Abstract: A filtering attachment is provided for the reduction of common-mode noise in systems. The filtering attachment includes a connector, a ferrite fitted around the connector and a conductive bracket which serves to secure the ferrite around the connector as well as comprising a shunting capacitance for increased filtering.
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: October 24, 1995
    Inventor: Boris Shusterman
  • Patent number: 5446427
    Abstract: The present invention relates to a balanced low-pass filter characterized in comprising a pair of input terminals and a pair of output terminals, wherein a pair of coils is connected in series in a negatively coupled manner between a first input terminal and a first output terminal and a pair of coils is connected in series in a negatively coupled manner between a second input terminal and a second output terminal, the connection point between each pair of coils and each end of each coil opposite to the connection point being connected across to the corresponding point of the corresponding pair of coils, with capacitors therebetween, and the coils being wound on the same bobbin in such a manner that each pair of negatively coupled coils is formed in adjacent winding portions.
    Type: Grant
    Filed: May 13, 1994
    Date of Patent: August 29, 1995
    Assignee: Toko Kabushiki Kaisha Toshiba
    Inventors: Kazuhiro Nakayama, Ikuo Ochiai, Michiya Nakazawa