Patents by Inventor Chi Yao Wu

Chi Yao Wu 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: 5767638
    Abstract: A method of driving an electric motor having at least one coil winding comprising using a switching operation when the current in the winding is to be switched from a first state to a second state. The switching operation has at least first and second switching steps, the interval between which is approximately equal to half the period of a dominant frequency of vibration of the motor (or to an integral multiple of the period plus a half). This reduces vibrations causing acoustic noise, enabling the motor to be operated more quietly. One or more intermediate steps may be included in the switching operation.
    Type: Grant
    Filed: February 22, 1996
    Date of Patent: June 16, 1998
    Assignee: The University of Warwick
    Inventors: Chi Yao Wu, Charles Pollock