Patents by Inventor Alastair Fields

Alastair Fields 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).

  • Method and apparatus for generating an electronic test signal
    Patent number: 6944569
    Abstract: The present invention relates to a method and an apparatus for generating an electronic test signal, and particularly to the use of such a method and apparatus for calibrating meters used to measure electrical characteristics such as voltage, current, phase angle and power. A user may select via a user input control the frequency domain characteristics of a desired electronic test signal including a user-defined set of amplitudes and phases of a fundamental frequency and one or more harmonic frequencies. A processor generates from the user-defined set of amplitudes and phases a frequency domain output set of amplitudes and phases for the fundamental frequency and one or more harmonic frequencies, which is then converted into a first time domain set of amplitudes extending over at least one cycle of the fundamental frequency. The first time domain set of amplitudes is communicated to a digital-to-analog output stage which generates an electronic test signal corresponding to the time domain set of amplitudes.
    Type: Grant
    Filed: April 1, 2003
    Date of Patent: September 13, 2005
    Assignee: Fluke Precision Measurement Ltd.
    Inventors: Philip James Harbord, Alastair Fields
  • Method and apparatus for generating an electronic test signal
    Publication number: 20040220766
    Abstract: The present invention relates to a method and an apparatus for generating an electronic test signal, and particularly to the use of such a method and apparatus for calibrating meters used to measure electrical characteristics such as voltage, current, phase angle and power. A user may select via a user input control the frequency domain characteristics of a desired electronic test signal including a user-defined set of amplitudes and phases of a fundamental frequency and one or more harmonic frequencies. A processor generates from the user-defined set of amplitudes and phases a frequency domain output set of amplitudes and phases for the fundamental frequency and one or more harmonic frequencies, which is then converted into a first time domain set of amplitudes extending over at least one cycle of the fundamental frequency. The first time domain set of amplitudes is communicated to a digital-to-analog output stage which generates an electronic test signal corresponding to the time domain set of amplitudes.
    Type: Application
    Filed: April 1, 2003
    Publication date: November 4, 2004
    Inventors: Philip James Harbord, Alastair Fields