Patents by Inventor Doc Liu

Doc Liu 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).

  • Current control method and device for a motor that is operable in a generator mode
    Patent number: 6384553
    Abstract: A system includes a battery, a motor, a switching circuit that interconnects the battery and the motor, a switch driving circuit that is connected to the switching circuit, and a controller that is connected to the switch driving circuit for controlling operation of the switching circuit in one of a first mode, wherein the motor is configured so as to draw power from the battery and wherein the motor rotates in a positive direction and with a positive torque, and a second mode, wherein the motor is configured so as to supply power to the battery and wherein the motor rotates in the positive direction and with a negative torque.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: May 7, 2002
    Assignee: Universal Scientific Industrial Co., Ltd.
    Inventor: Doc Liu