Patents by Inventor Ki Bui Ma

Ki Bui Ma has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6231011
    Abstract: A torque/reactive momentum wheel control system for use in satellites for dynamic attitude maintenance and alteration where the flywheel of each momentum wheel is levitated by a high-temperature superconducting element repulsively interacting with permanent magnets in the flywheel. The spin rate (rpm) of the flywheel being controlled by either an active magneto or electromagneto drive system. Each momentum wheel is cooled by a cryo-cooler and can have a total weight of about 10 Kg to a fraction of 1 Kg and delivering 3.5 Js with less than 1 W loss.
    Type: Grant
    Filed: November 2, 1998
    Date of Patent: May 15, 2001
    Assignee: University of Houston System
    Inventors: Wei-Kan Chu, Ki Bui Ma, Jang-Horng Yu, Quark Yung-Sung Chen, Eujeong Lee, Yevgeniy Postrekhin
  • Patent number: 5947237
    Abstract: Disclosed are devices for influencing and/or controlling relative motion between members, such as vibration damping or absorbing devices, clutches and brakes. The devices comprise a magnet on one member and a field cooled superconductor on the other member. The devices utilize the interaction of the magnetic field of the magnet as it moves through the pinned flux in the superconductor to either influence or control relative motion.
    Type: Grant
    Filed: August 29, 1995
    Date of Patent: September 7, 1999
    Assignee: University of Houston - University Park
    Inventors: Chase K. McMichael, Ki-Bui Ma, Wei-Kan Chu
  • Patent number: 5831362
    Abstract: Disclosed is a flywheel system for storing kinetic energy which utilizes a high temperature superconductor/magnet system for the flywheel bearings. The flywheel includes a first magnet, and having a ring magnet defining an opening. The levitation system includes a magnet for attractively interacting with first flywheel magnet, with a high temperature superconductor interposed between them, and further includes a magnet system for repulsively interacting with and partially inserted into the ring magnet.
    Type: Grant
    Filed: July 16, 1997
    Date of Patent: November 3, 1998
    Assignee: The University of Houston
    Inventors: Wei-Kan Chu, Quark Yung-Sung Chen, Ki-Bui Ma, Harold Zule Xia, Mark Alan Lamb, Rodger Sheldon Cooley, Chase Kenyon McMichael
  • Patent number: 5726512
    Abstract: An isolation system for isolating a first object from vibrations from a second object. Such vibrations will have three orthogonal components, one oriented along a line between the objects, and two oriented 90.degree. apart in a plane normal to that line. The system includes three superconductor/magnet stages, each stage designed to extinguish one of the orthogonal components.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: March 10, 1998
    Assignee: The University of Houston System
    Inventors: Wei-Kan Chu, Quark Yung-Sung Chen, Ki-Bui Ma, Mark Alan Lamb, Chase Kenyon McMichael, Ignatius S. T. Tsong
  • Patent number: 5542506
    Abstract: Disclosed are devices for influencing and/or controlling relative motion between members, such as vibration damping or absorbing devices, clutches and brakes. The devices comprise a magnet on one member and a field cooled superconductor on the other member. The devices utilize the interaction of the magnetic field of the magnet as it moves through the pinned flux in the superconductor to either influence or control relative motion.
    Type: Grant
    Filed: December 3, 1991
    Date of Patent: August 6, 1996
    Assignee: University of Houston-University Park
    Inventors: Chase K. McMichael, Ki-Bui Ma, Wei-Kan Chu
  • Patent number: 5159219
    Abstract: A superconductor-magnet system having high thrust and stability, with a method for increasing the thrust and stability of such a system, comprises a first magnet, a second magnet and a superconductor. The magnets are in motion relative to each other and the superconductor is in motion relative to one and stationary relative to the other magnet. High thrust and stability can be achieved by increasing the magnetic field of the magnet in motion relative to the superconductor. Also disclosed are magnetic thrust and journal bearings utilizing the above system.
    Type: Grant
    Filed: May 16, 1991
    Date of Patent: October 27, 1992
    Assignee: University of Houston-University Park
    Inventors: Wei-Kan Chu, Ki-Bui Ma, Chase K. McMichael
  • Patent number: 5039951
    Abstract: A Josephson junction (100) is employed as a very-high-speed frequency demodulator for detecting a frequency-shift-keyed (FSK) modulated signal (201) in a microwave or lightwave communication system. The voltage induced across the junction in response to an incident FSK modulated radiation signal follows the frequency variations in the incident wave thereby directly demodulating the information signal from its carrier. In the disclosed embodiment an FSK modulated optical signal is mixed with a local oscillator (303) signal, which is then incident on a photodetector (305). The resultant microwave-frequency signal is then applied over a two-wire transmission line (308) to the Josephson junction (307) for direct demodulation.
    Type: Grant
    Filed: October 30, 1990
    Date of Patent: August 13, 1991
    Assignee: Bell Communications Research, Inc.
    Inventors: Nim K. Cheung, James L. Gimlett, Ki Bui Ma