Patents by Inventor Douglas A. Hartzell

Douglas A. Hartzell 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).

  • Patent number: 6822457
    Abstract: A method of precisely determining velocity of propagation and the location of a fault on an electric transmission line, using a system of high frequency transmitter and receiver combinations to monitor and detect high frequency bursts produced by the transmitters and by faults, including memory and analysis capability to store and analyze high frequency data before and after a detected fault.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: November 23, 2004
    Inventors: Marshall B. Borchert, Douglas A. Hartzell
  • Publication number: 20040189317
    Abstract: A method of precisely determining velocity of propagation and the location of a fault on an electric transmision line, using a system of high frequency transmitter and receiver combinations to monitor and detect high frequency bursts produced by the transmitters and by faults, including memory and analysis capability to store and analyze high frequency data before and after a detected fault.
    Type: Application
    Filed: September 29, 2003
    Publication date: September 30, 2004
    Inventors: Marshall b. Borchert, Douglas A. Hartzell
  • Patent number: 5461318
    Abstract: A method for detecting impedance discontinuities in two-conductor cable includes the initial step of transmitting a pulse of energy onto the cable and receiving any reflected pulses at a base location. The distance to the discontinuity is calculated by measuring the elapsed time between the transmitted and received pulses. A waveform is created on a display screen to shown the transmitted and reflected pulses, by taking a plurality of horizontal samples along the cable, and calculating a vertical value for each horizontal sample taken. Each horizontal sample is then converted to digital form and displayed on the screen. Another step in the method includes determining the gauge of the cable and then subtracting the exponential decay of the transmitted pulse waveform based upon that determined cable gauge so as to create a modified transmitted pulse which is displayed on the screen.
    Type: Grant
    Filed: June 8, 1994
    Date of Patent: October 24, 1995
    Inventors: Marshall B. Borchert, Douglas A. Hartzell, Edward J. Thomassen, Lee M. Rezac