Patents by Inventor David L. Chu

David L. Chu 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: 5022268
    Abstract: Vibrational Analysis technology translates acoustic/vibratory energy created by industrial processes into useful, process-related information. This invention enables a non-acoustical expert to easily collect and interpret the data.
    Type: Grant
    Filed: May 22, 1989
    Date of Patent: June 11, 1991
    Assignee: Exxon Research and Engineering Company
    Inventors: H. Alan Wolf, David L. Chu
  • Patent number: 4523269
    Abstract: A DC to N phase AC converter, where N is an integer greater than 2, includes a DC source having first and second terminals for deriving equal amplitude opposite polarity DC voltages, a series resonant circuit, and N output terminals, one for each phase of the converter. The series resonant circuit is selectively connected in series with the first and second terminals and the N output terminals for an interval equal to one half cycle of the resonant circuit resonant frequency, so that current flows between a selected one of the first and second terminals and the resonant circuit and a selected one of the N output terminals during the interval. The resonant circuit current is zero at the beginning and end of the interval. A capacitor shunting each of the output terminals has a value relative to the capacitance of the series resonant circuit such that the voltage across each output terminal remains approximately constant between adjacent exchanges of energy between the resonant circuit and the output terminal.
    Type: Grant
    Filed: November 16, 1983
    Date of Patent: June 11, 1985
    Assignee: Reliance Electric Company
    Inventors: Richard H. Baker, David L. Chu, Derek Chambers