Patents by Inventor Todd P. Kelsey

Todd P. Kelsey 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).

  • Telecommunications off-hook and intrusion detection method and apparatus
    Patent number: 6470083
    Abstract: A method and apparatus to detect off-hook and intrusion conditions on a telephone line. A voltage to frequency converter is used to convert the voltage measured between the TIP and RING terminals of a telephone line to a frequency. The voltage is continuously monitored, once during each sample period. The measured frequency is compared to predetermined threshold values to determine the state of the telephone line. The predetermined threshold values are updated in each sample period.
    Type: Grant
    Filed: December 24, 1997
    Date of Patent: October 22, 2002
    Assignee: ABB Automation Inc.
    Inventors: Rodney C. Hemminger, Albert H. Maxwell, Jr., Michael A. Murphy, Thomas J. Van Heuklon, Richard L. Tenor, Todd P. Kelsey, Fred F. Schleifer