Patents Examined by Jeff Sterrett
  • Patent number: 5291383
    Abstract: A UPS system comprising a resonant control circuit 100, a gate drive circuit 200, a resonant converter 300, a bootstrap power supply circuit 400 for supplying an isolated DC supply voltage to the resonant control circuit, a bootstrap battery charger 500, and a variable speed fan drive circuit 600.
    Type: Grant
    Filed: September 2, 1992
    Date of Patent: March 1, 1994
    Assignee: Exide Electronics Corporation
    Inventor: George Oughton
  • Patent number: 5175675
    Abstract: A switching regulator, which applies output DC voltage to a load via an oscillator oscillatable between ON and OFF states, has an oscillation controller to control the oscillation of the oscillator based on the load so that a frequency of the oscillating of the oscillator is kept lower than a predetermined frequency irrespective of the load.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: December 29, 1992
    Assignee: Ricoh Company, Ltd.
    Inventor: Hiroshi Uramoto
  • Patent number: 5006973
    Abstract: A resonant, quasi-square wave, pulse width modulated (PWM) power source (33) for a connectorless power system is disclosed. The power source (33) supplies constant amplitude, fixed-frequency current to a supply loop (31) that is inductively coupled to a plurality of pickup loops (35), each of which supplies power to a remote unit, such as the seat regulator that supplies power to a group of commercial airplane seats (37). Precise, fixed-frequency control is provided by triggering a PWM with fixed-frequency sync pulses. Current control is provided by sensing the current applied to the supply loop, converting the magnitude of the sensed current to a voltage and using the voltage to control the width of the pulses produced by the PWM. The PWM pulses, in turn, control the width of the power pulses applied by the power source (33) to the supply loop (31). Stability and efficiency are improved by maintaining the output of the power source nearly resonant, i.e.
    Type: Grant
    Filed: March 28, 1990
    Date of Patent: April 9, 1991
    Assignee: The Boeing Company
    Inventor: James B. Turner
  • Patent number: 5001622
    Abstract: In a pulse width modulated inverter, the fit of a selected switching angle is monitored by counting zero crossings in a neighborhood of the function ##EQU1## for each harmonic of interest. If the fit is bad, a switching angle is moved to improve the fit.
    Type: Grant
    Filed: May 10, 1990
    Date of Patent: March 19, 1991
    Assignee: Sundstrand Corporation
    Inventors: Maurice A. Kirchberg, Jr., Alexander Cook
  • Patent number: 4985821
    Abstract: Disclosed are circuits for indirectly sensing and controlling the output current of switching type DC to DC converters utilizing capacitance which follows the output voltage by being responsive to switching current during the conduction period and being controllably discharged as a function of output voltage during the non-conduction period.
    Type: Grant
    Filed: April 16, 1990
    Date of Patent: January 15, 1991
    Assignee: Lambda Electronics Inc.
    Inventor: Itzchak Cohen
  • Patent number: 4933830
    Abstract: A switching power supply using a step-up transformer whose impedance viewed from its primary side is different from the impedance viewed from its secondary side whereby the inductance of its primary and secondary windings are settable independently of each other.
    Type: Grant
    Filed: April 27, 1989
    Date of Patent: June 12, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Masayoshi Sato, Norikazu Tokunaga, Hisao Amano, Yasuo Matsuda
  • Patent number: 4926304
    Abstract: A switched-mode power supply circuit for converting a DC input voltage into a DC output voltage comprises a series arrangement of a controllable power switch and an inductive element coupled between the input voltage terminals. Control means are provided for rendering the power switch alternately conducting and non-conducting and a rectifier is coupled to the inductive element for making the output voltage available. The inductive element and a capacitor coupled thereto form a part of a resonant circuit in which a voltage oscillation is present in the time periods when the switch and the rectifier are currentless. The circuit further comprises means for interrupting the oscillation present in the resonant circuit at an instant when the voltage across the inductive element or the current through the capacitor is substantially zero. In one embodiment, the dissipation in the circuit is reduced and the circuit is synchronized.
    Type: Grant
    Filed: May 4, 1989
    Date of Patent: May 15, 1990
    Assignee: U.S. Philips Corporation
    Inventor: Antonius A. M. Marinus
  • Patent number: 4853609
    Abstract: An opposite-phase current source is improved by eliminating the conventionally employed current mirror circuits, and by instead using a pair of transistor current sources subjected to voltage feedback and emitter-connected via a resistor. A constant current source or sources are coupled to the opposite ends of the resistor or to a mid-point thereof.
    Type: Grant
    Filed: June 9, 1983
    Date of Patent: August 1, 1989
    Assignee: Pioneer Electronic Corporation
    Inventors: Tatsuo Numata, Tadashi Noguchi