Patents by Inventor David Maxwell Coombs

David Maxwell Coombs 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).

  • System and method for increasing the efficiency of alternating current induction motors
    Patent number: 5723966
    Abstract: A system for increasing the efficiency of single and multi-phase induction motors. The system is comprised of a microcontroller which combines a time when the AC line current reaches zero amps with a time when AC line voltage to the AC motor reaches zero volts and with a digital measurement provided by an A/D converter to determine a servo error. The servo error determines whether the A/C motor needs more or less power. The microprocessor provides a control signal to a switching means to supply the minimum power required based on the servo error.
    Type: Grant
    Filed: August 23, 1996
    Date of Patent: March 3, 1998
    Assignee: Current Technology, Inc.
    Inventors: Richard Stephen Straka, David Maxwell Coombs