Patents by Inventor Minh Q. Tu

Minh Q. 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).

  • Patent number: 4829222
    Abstract: A driver circuit is under the control of a microprocessor and in communication with a stepper motor. The stepper motor is in driving communication with a mechanism. A power source having a first and second voltage level is in communication with the stepper motor such that the first voltage level is in direct communication with the power terminal of the stepper motor. The second voltage level can be selectively applied to the power terminal of the stepper motor upon instruction of the microprocessor to a gate circuit of the driver circuit. The driver circuit also includes a gating amplifier having a plurality of stages, each stage in communication with a respective one of the stepping terminals of said stepper motor. A coupling circuit means is provided for receiving a series of step commands from said microprocessor and turning "ON" or "OFF" a respective stage of said gating amplifier in accordance with a respective step command in the form of a binary set number.
    Type: Grant
    Filed: August 19, 1987
    Date of Patent: May 9, 1989
    Assignee: Pitney Bowes Inc.
    Inventors: Richard A. Hallenbeck, Minh Q. Tu