Patents by Inventor Norman W. Ritchie

Norman W. Ritchie 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).

  • Filter-switched drive operating mode control
    Patent number: 6700762
    Abstract: A controller for a pulse width modulated electrical drive or a dual-mode, pulse width modulated/variable voltage inverter drive is coupled to sensors within a filter at the drive output. Upon detecting failure of the filter or filter components (e.g., a capacitor short or blown fuse) through the sensors, the controller either shuts down the drive or automatically switches the drive operating mode to an output mode which does not require filtering. Damage to the electrical system or downhole equipment from transmission of unfiltered or improperly filtered power may thus be averted upon failure of the filter or a filter component.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: March 2, 2004
    Assignee: Baker Hughes Incorporated
    Inventors: Michael Underwood, Ryan B. Ashbaugh, Norman W. Ritchie
  • Filter-switched drive operating mode control
    Publication number: 20020024783
    Abstract: A controller for a pulse width modulated electrical drive or a dual-mode, pulse width modulated/variable voltage inverter drive is coupled to sensors within a filter at the drive output. Upon detecting failure of the filter or filter components (e.g., a capacitor short or blown fuse) through the sensors, the controller either shuts down the drive or automatically switches the drive operating mode to an output mode which does not require filtering. Damage to the electrical system or downhole equipment from transmission of unfiltered or improperly filtered power may thus be averted upon failure of the filter or a filter component.
    Type: Application
    Filed: August 31, 2001
    Publication date: February 28, 2002
    Applicant: BAKER HUGHES INCORPORATED
    Inventors: Michael Underwood, Ryan B. Ashbaugh, Norman W. Ritchie