Patents Examined by Aditya Krishnan
  • Patent number: 5689410
    Abstract: A rectifier architecture with a split boost circuit having protection circuitry for protecting circuit elements of the split boost. The split boost includes a voltage input terminal, an inductor, two voltage output terminals, a boost diode and branches A and B. Each branch A and B, includes: a switch, a protection circuit, and a capacitor. In a preferred embodiment, the protection circuit is a parallel resistor-diode pair coupled between the capacitor and the switch. The purpose of the protection circuit is to limit circulating current between capacitors when switches in branches A and B are active.
    Type: Grant
    Filed: June 21, 1996
    Date of Patent: November 18, 1997
    Assignee: Lucent Technologies Inc.
    Inventor: Yimin Jiang
  • Patent number: 5689412
    Abstract: This invention is a multi-function power supply, i.e., a power-mate unit, for providing DC input to a portable electronic device, e.g., a notebook computer, operable with a rechargeable battery. The power-mate unit includes an AC plug for electrically connecting to an AC power source for receiving the AC input current. The power-mate unit further includes an AC/DC power supply for converting the AC input current to an external DC operation current suitable for operating the portable electronic device. The power-mate unit further includes a backup battery pack connected to the AC/DC power supply for receiving a backup battery charging current for charging the backup battery pack wherein the backup battery pack further providing a backup DC current to the portable electronic device. The power-mate unit further includes a backup battery monitoring and display for continuously monitoring a charge capacity of the backup battery pack and for displaying the charge capacity.
    Type: Grant
    Filed: April 14, 1995
    Date of Patent: November 18, 1997
    Assignee: Delta Green Energy, Inc.
    Inventor: James Chin-Ming Chen
  • Patent number: 5686822
    Abstract: A current generator and method of making a current generator in which two resistors are provided, each in series with one of two transistors in the generator, and in which one of the resistors is trimmed if the reference current is too large and the other is trimmed if the reference current is too small, thereby obviating the problems of the prior art in which one resistor must be trimmed by a potentially large and unacceptable amount. The two resistors are formed with a distribution of resistances which is centered on their corresponding target resistance values so that the number of resistors to be trimmed and the amount of trimming per resistor are reduced. The appropriate target resistances of the resistors can be determined if a maximum trim factor is set. The method is insensitive to variations in the process by which the resistances of the resistors are initially set and reduces the variability of the untrimmed reference current with respect to resistor critical dimensions.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: November 11, 1997
    Assignee: Harris Corporation
    Inventors: Gregg Douglas Croft, Sang-Gug Lee, Steven Robert Jost
  • Patent number: 5686827
    Abstract: An apparatus includes a Hall effect device which generates an electrical output signal upon exposure to a magnetic field. An operating current for the Hall effect device is varied by input circuitry to maintain the output signal from the Hall effect device constant with variations in temperature of the Hall effect device while the magnetic field to which the Hall effect device is exposed remains constant. The input circuitry includes a temperature responsive element which is maintained at a temperature which varies as a function of variations in the temperature of the Hall effect device. The temperature responsive element is a silicon diode.
    Type: Grant
    Filed: February 9, 1996
    Date of Patent: November 11, 1997
    Assignee: Eaton Corporation
    Inventor: Charles E. Ward
  • Patent number: 5686879
    Abstract: This ammeter comprises an element made of magnetoresistive material in a thin layer located on a first face of a substrate; first connection means connected to the magnetoresistive element in two zones along a first direction (XX') and enabling the element to be supplied with current; second connection means connected to the magnetoresistive element in two zones located along a second direction (YY') perpendicular to the first direction (XX'). This ammeter enables the measurement of the value of the current flowing in a conductor preferably oriented in a direction (ZZ') parallel to the first direction (XX').
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: November 11, 1997
    Assignee: Thomson-CSF
    Inventors: Alain Schuhl, Frederic Nguyen Van Dau
  • Patent number: 5684687
    Abstract: A driver circuit for an inverter includes a switching circuit formed of a first switching element and a second switching element connected in series, which are turned on and off in complementary with one another; a first DC power supply connected parallel to the switching circuit; a first driver circuit connected to the first switching element for driving the same; a second driver circuit connected to the second switching element for driving the same; a second DC power supply connected to the second driver circuit for supplying electric power to the second driver circuit; and a first capacitor connected to the first driver circuit and having a charge-up path communicating with the second DC power supply. During an ON-period of the second switching element, the first capacitor is charged up through the second DC power supply and supplies electric power to the first driver circuit.
    Type: Grant
    Filed: December 11, 1995
    Date of Patent: November 4, 1997
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Takao Ichihara
  • Patent number: 5684678
    Abstract: An LC resonant circuit for a resonant converter includes a resonant capacitor and an inductor coupled to a fixed frequency AC supply. A controlled inductor in parallel with the resonant capacitor is controlled by a DC current to vary its inductance. The controlled inductor comprises a magnetic core having one or more power windings, and a control winding wound on the core. The DC current in the control winding produces core flux which effects core permeability. The controlled inductor has the effect of changing the capacitor impedance and thus influences the converter output. Multiple, independently controlled and regulated outputs may be driven by one power switching stage.
    Type: Grant
    Filed: December 8, 1995
    Date of Patent: November 4, 1997
    Assignee: Delco Electronics Corp.
    Inventor: Alfred Henry Barrett
  • Patent number: 5682128
    Abstract: A reentrant resonator has a center conductor fixed to an end wall and surrounded by side walls of a housing, where end walls, side walls, and center conductors are all coated with a high-temperature superconducting material. The end walls, side walls, and center conductors are shaped so as to merge smoothly between the side wall and end wall, and end wall and center conductor in order to avoid any corners or right angles. The absence of corners and right angles allows the surface of the coating of high-temperature superconducting material to avoid electromagnetic discontinuities. A cover for the resonator has a tuning device consisting of a bracket receiving a bolt. When the bolt is rotated, an end of the bolt engages the cover to force a surface of the cover closer to the center conductor in order to tune the resonator.
    Type: Grant
    Filed: April 23, 1996
    Date of Patent: October 28, 1997
    Assignee: Illinois Superconductor Corporation
    Inventor: Qiang Huang
  • Patent number: 5675479
    Abstract: When the disclosed switching power supply is lightly loaded, efficiency is improved by lowering the switching frequency of a switching element. When its load is heavy, ripple noise of the output voltage is reduced by heightening the switching frequency of the switching element, and transient response is improved. The switching power-supply employs an RCC method and also includes an oscillation frequency inhibit circuit for inhibiting an oscillation frequency, and an operation switching circuit for starting or stopping the operation of the oscillation frequency inhibit circuit. By applying a signal voltage to the operation switching circuit, the operation of the oscillation frequency inhibit circuit is turned on while a load is light and turned off while a load is heavy, and a normal RCC oscillation operation is performed.
    Type: Grant
    Filed: July 25, 1996
    Date of Patent: October 7, 1997
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Ryota Tani, Kohji Nakahira
  • Patent number: 5675305
    Abstract: A ferromagnetic flux path (20) extends between pole pieces (30,32). A superconducting coil (62) in series with a persistence switch (64) encircles the flux path. A pair of resistive coils (50,52) are disposed one at each pole piece. The resistive coils are overdriven near to the point of thermal failure to produce a 0.5 T or other preselected field strength in a gap between the pole pieces. The persistence switch is closed to stabilize and hold the flux through the superconducting coil. The resistive magnets are ramped down or shut off. During imaging, a smaller amount of current is directed to the resistive coils to supplement and focus the magnetic field from the superconducting coil through the gap between the poles. In this manner, high strength magnetic fields are generated in the gap using a relatively inexpensive combination of resistive and superconducting coils.
    Type: Grant
    Filed: July 17, 1996
    Date of Patent: October 7, 1997
    Assignee: Picker International, Inc.
    Inventors: Gordon D. DeMeester, Michael A. Morich
  • Patent number: 5675486
    Abstract: An electric power circuit for producing a DC output from an AC output of an AC power source comprises a rectifying circuit to be connected to the AC power source for rectifying the AC output to produce a rectified output, and a smoothing circuit comprising an electrolytic capacitor connected to the rectifying circuit and having an output port to be connected to a load, for smoothing the rectified output to produce a smoothed output as the DC output onto the output port. The DC output is supplied to the load connected to the output port so that a load current flows from the power circuit through the load. In order to reduce harmonic components flowing back to the AC power source due to ripple component included in the load current, a non-linear resistance element having a positive temperature coefficient of resistance is used in a positive one of connection lines connecting the rectifying circuit and the smoothing circuit.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: October 7, 1997
    Assignee: Jelmax Co., Ltd.
    Inventor: Kazuo Ishii
  • Patent number: 5671128
    Abstract: A power supply apparatus in which a series circuit of first and second switching elements not blocking their reverse-directional currents is connected in parallel to a series circuit of a D.C. power source and a capacitor, a primary winding of a transformer is connected between a junction point of the D.C. power source and capacitor and a junction point of the switching elements, a secondary winding of the transformer is connected to a load circuit, and a controller is provided for controlling ON and OFF operation of the switching elements to cause a switching frequency of the switching elements to be set higher than a resonance frequency of the capacitor and an inductance of the transformer and to cause a voltage across the capacitor to increase.
    Type: Grant
    Filed: February 12, 1996
    Date of Patent: September 23, 1997
    Assignee: Matsushita Electric Works, Ltd.
    Inventors: Toshiaki Nakamura, Haruo Nagase, Hiroichi Shinbori
  • Patent number: 5671129
    Abstract: The invention is directed to an electronic switched-mode power supply for supplying power to an accumulator (61), comprising a self-oscillating flyback converter having a transformer (50), a switching transistor (1) with an emitter resistor (22) and a feedback circuit (11, 27). A control circuit (St) inhibits conduction of the switching transistor (1) when the switching voltage at the accumulator (61) has reached a predetermined upper level (A). A switching arrangement (SE) lowers the upper switching voltage (A) to a lower switching voltage (B) when, with the switched-mode power supply in the pulsed mode, the ratio of the duration of oscillation pauses to the duration of oscillation bursts exceeds a specified magnitude.
    Type: Grant
    Filed: August 4, 1995
    Date of Patent: September 23, 1997
    Assignee: Braun Aktiengesellschaft
    Inventor: Gerhard Lang
  • Patent number: 5668713
    Abstract: In a method of controlling an inverter for adjusting a periodic inverter output waveform to a desired periodic waveform, an error waveform pattern between an inverter output waveform of the present prescribed period and a desired periodic waveform generated in synchronization with the prescribed period is formed, and the error waveform pattern is added to an inverter driving waveform pattern in the last prescribed period, whereby an inverter driving waveform pattern is updated.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: September 16, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masaki Eguchi, Hirokazu Kodama, Tsukasa Takebayashi, Hirofumi Nakata
  • Patent number: 5668712
    Abstract: A circuit for controlling a DC/AC converter of a power supply circuit for a motor vehicle headlight discharge lamp, the circuit comprising a primary circuit, voltage-feed means for feeding the primary circuit with voltage, and a secondary circuit coupled to the primary circuit by mutual induction, the secondary circuit delivering a voltage controlling the non-conductive and conductive state of a MOSFET type transistor of the DC/AC converter, the voltage that the power supply means deliver to the primary circuit constituting a modulated high frequency carrier voltage, the secondary circuit including means for converting the high frequency voltage delivered to the primary circuit into a control voltage for the transistor that is greater than or less than a given non-conductive or conductive threshold, as a function of the modulation of said high frequency voltage, the conversion means of the secondary circuit including a switch connected between the grid and the source of the transistor, said switch being open
    Type: Grant
    Filed: March 29, 1996
    Date of Patent: September 16, 1997
    Assignee: Valeo Electronique
    Inventors: Bruno Cassese, Patrick Wacheux, Gilles Paul, Eric Herzberger, Jean-Marc Nicolai
  • Patent number: 5668467
    Abstract: A current regulator includes a regulation stage and a start-up stage. The regulation stage has a base bus and an output transistor having a base coupled to the base bus for generating a regulated current. The regulation stage also includes a current maintaining transistor coupled to the base bus for inducing and maintaining an operating current in the base bus in response to a start-up current first being induced in the base bus. The start-up stage includes a start-up transistor coupled to the base bus for inducing the start-up current in the base bus before the current maintaining transistor is turned on. The start-up transistor is turned off by the regulation stage after the current maintaining transistor is maintaining the operating current in the base bus.
    Type: Grant
    Filed: February 17, 1995
    Date of Patent: September 16, 1997
    Assignee: National Semiconductor Corporation
    Inventor: Robert Allen Pease
  • Patent number: 5668707
    Abstract: A multi-phase AC to DC harmonic neutralizing power converter. The power converter includes a plurality of non-isolated inputs for respective phases of a multi-phase source of AC power and a plurality of first rectifiers connected respectively to the inputs. A multi-phase harmonic neutralizing converter includes a power switching inverter having an input connected to the outputs of each of the first rectifiers, the inverter including LC resonant circuits. A plurality of second rectifiers having respective inputs connected to the output of the inverter through a plurality of respective transformers having outputs that are connected in voltage additive relationship to the outputs of the respective individual phase first rectifiers.
    Type: Grant
    Filed: October 4, 1994
    Date of Patent: September 16, 1997
    Assignee: Delco Electronics Corp.
    Inventor: Alfred Henry Barrett
  • Patent number: 5666097
    Abstract: A magnetizer for use in forming periodic magnetic fields is provided which utilizes two magnet structures which are coaxially aligned with one another. Two stages of magnetic cores are inserted into a gap between the two magnet structures. The stages of magnetic cores each have an upper and lower portion, each portion of which has grooves and ridges which mirror each other. The two different stages of magnetic cores are fabricated such that the respective grooves and ridges are offset and the grooves and ridges of one stage of magnetic core opposes the grooves and ridges, respectively, of the other stage of magnetic core. The two stages of magnetic cores can be active or passive magnetic material. In operation, the two magnetic structures form a uniform transverse magnetic field which passes through a working cavity of the magnetizer.
    Type: Grant
    Filed: June 14, 1996
    Date of Patent: September 9, 1997
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventor: Herbert A. Leupold
  • Patent number: 5666047
    Abstract: A dielectric power transformer comprises a tuning inductor having a nonmatic core connected in parallel with a capacitive voltage divider. The dielectric power transformer transforms the voltage of an alternating current power source connected across the inductor into a voltage across a load connected to the capacitive voltage divider. The dielectric power transformer has a resonant frequency substantially equal to the frequency of the power source.
    Type: Grant
    Filed: October 5, 1995
    Date of Patent: September 9, 1997
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Leopold J. Johnson, Russell E. Hammond
  • Patent number: 5663541
    Abstract: A manual switch for direct current reversible electric winch motors, which switch includes a switch housing that may be mounted on or built into the winch housing of an electric winch or connected by means of appropriate wiring to the electric winch motor for operating the winch under circumstances where automatic operation of the winch is not possible. The switch housing includes four fixed contacts that are electrically isolated from each other and from the housing and a pair of contact bars which are spring-loaded inside the housing to facilitate selective engagement with the respective fixed contacts responsive to manual operation of the switch to operate the reversible electric winch motor in the forward or reverse direction.
    Type: Grant
    Filed: March 18, 1996
    Date of Patent: September 2, 1997
    Inventor: George M. Mc Gregor, II