Patents by Inventor Edwin W. Rowand

Edwin W. Rowand 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).

  • Direct digital synthesizer phase locked loop
    Patent number: 6664827
    Abstract: Phase locked loops adapted to filter and store data indicative of the control signal applied to an oscillator permit suppression of tracking in the event of a step change in the phase difference between the reference clock signal and the feedback signal in the phase locked loop. Such phase locked loops further facilitate compensation for drift of the oscillator. Such phase locked loops are suitable for use in timing circuits of communications systems.
    Type: Grant
    Filed: March 1, 2002
    Date of Patent: December 16, 2003
    Assignee: ADC Telecommunications, Inc.
    Inventors: William O'Leary, Edwin W. Rowand
  • Direct digital synthesizer phase locked loop
    Publication number: 20020180498
    Abstract: Phase locked loops adapted to filter and store data indicative of the control signal applied to an oscillator permit suppression of tracking in the event of a step change in the phase difference between the reference clock signal and the feedback signal in the phase locked loop. Such phase locked loops further facilitate compensation for drift of the oscillator. Such phase locked loops are suitable for use in timing circuits of communications systems.
    Type: Application
    Filed: March 1, 2002
    Publication date: December 5, 2002
    Inventors: William O'Leary, Edwin W. Rowand
  • Method and apparatus for harmonic distortion correction
    Patent number: 5377092
    Abstract: There is described a method and apparatus for substantially cancelling harmonic distortion from the output voltage signal of a power supply. The system samples the output of the power supply and detects the harmonic distortion within the output signal. After the harmonic distortion is detected, the amplitude of the real and imaginary components of the harmonic distortion are determined. The amplitude components are applied to a PI compensator to generate the harmonic distortion correction signal necessary to substantially cancel harmonic distortion from the output voltage signal. The harmonic distortion correction signal is then applied to the power supply.
    Type: Grant
    Filed: November 16, 1992
    Date of Patent: December 27, 1994
    Assignee: International Power Machines
    Inventors: Edwin W. Rowand, Jr., Donald J. Lucas