Patents by Inventor Robert Zijlstra

Robert Zijlstra 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 sensor apparatus and method for uninterruptible power supply
    Patent number: 7550872
    Abstract: A UPS has a current sensor for controlling operation of a UPS main power circuit positioned in series with the AC supply voltage so as to measure the net current used by each component connected to the UPS main power circuit. Feedback from the current sensor received by a control circuit is used to achieve unity power factor operation with the UPS. The current sensor location and operation is adaptable to both single phase and three phase operation.
    Type: Grant
    Filed: December 19, 2006
    Date of Patent: June 23, 2009
    Assignee: General Electric Company
    Inventors: Fokke Hoekstra, Robert Zijlstra, Chris van Kalken, Rajendra Naik, Pradeep V
  • CURRENT SENSOR APPARATUS AND METHOD FOR UNINTERRUPTIBLE POWER SUPPLY
    Publication number: 20080143187
    Abstract: A UPS has a current sensor for controlling operation of a UPS main power circuit positioned in series with the AC supply voltage so as to measure the net current used by each component connected to the UPS main power circuit. Feedback from the current sensor received by a control circuit is used to achieve unity power factor operation with the UPS. The current sensor location and operation is adaptable to both single phase and three phase operation.
    Type: Application
    Filed: December 19, 2006
    Publication date: June 19, 2008
    Inventors: Fokke Hoekstra, Robert Zijlstra, Chris van Kalken, Rajendra Naik, Pradeep V