Patents by Inventor Ian M. Woodhead

Ian M. Woodhead 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).

  • Dielectric constant monitor
    Patent number: 5148125
    Abstract: Monitoring of the average dielectric constant in an extended volume of a medium such as soil is achieved using an oscillator incorporating a transmission line to be embedded in the medium. The transmission line is connected as the feedback loop of an amplifier, for one-way propagation of an electrical signal with a delay determined largely by the dielectric properties of the medium, such as its moisture content. The oscillation frequency is indicative of the dielectric constant of the medium.
    Type: Grant
    Filed: June 21, 1991
    Date of Patent: September 15, 1992
    Assignee: Lincoln College
    Inventors: Ian M. Woodhead, Stephen J. J. Hirsch
  • Earth testing means for an electric fence network
    Patent number: 4771245
    Abstract: An earth testing means for monitoring the status of the earth return system of an electric fence network is arranged to indicate the potential difference between the earth return system of the electric fence and a secure earth. In one embodiment the earth testing means comprises an indicator to provide a quantitive display of the fence earth-secure earth potential difference.
    Type: Grant
    Filed: September 10, 1986
    Date of Patent: September 13, 1988
    Assignee: Development Finance Corporation
    Inventor: Ian M. Woodhead