Patents by Inventor Mai Xuan Tu

Mai Xuan Tu 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).

  • Mechanical-electric energy converter and watch part comprising this energy converter
    Patent number: 6041022
    Abstract: A mechanical-electric energy converter comprising a wheel for transmitting energy which rotates at a low speed. The teeth of the driving wheel shift the rotor of the generator from its position of equilibrium, causing it to oscillate around the wheel. This converter can produce high angular velocities without a speed-increasing gear train.
    Type: Grant
    Filed: June 15, 1999
    Date of Patent: March 21, 2000
    Assignee: Patek Philippe S.A.
    Inventors: Mai Xuan Tu, Michel Schwab, Jean-Pierre Musy
  • Method and device for feeding a single-phase stepping motor
    Patent number: 5774426
    Abstract: The method and the device for feeding a single-phase stepping motor for a timepiece are adapted to provide the motor (M) with a sequence of chopped voltage pulses of variable duration as a function of load conditions and of feed voltage. The sequence of chopped voltage pulses comprises in particular a supplementary sequence of partial voltage pulses of constant duration (T.sub.4), separated from each other by variable intervals (T.sub.5i) defined by a reference current (I.sub.ref) whose value is adapted as a function of the level of load of the motor.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: June 30, 1998
    Assignee: Detra SA
    Inventors: Mai Xuan Tu, Michel Schwab