Patents by Inventor John F. Hibbard

John F. Hibbard 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: 5686806
    Abstract: A three-phase, low-pass filter for use in an electronic speed control system and wherein an adjustable speed drive is disposed in signal transmitting relation relative to an electric motor by an electrical conduit having a predetermined length, and wherein each single-phase circuit of the three-phase, low-pass filter includes an inductor having input and output nodes, a first resistor electrically coupled in parallel to the inductor, a second resistor having input and output nodes, and wherein the input node of the second resistor is electrically coupled to the output node of the inductor, and a capacitor having input and output nodes, and wherein the input node of the capacitor is electrically coupled to the output node of the second resistor, and wherein the low-pass filter is electrically coupled to the electrical conduit and operable to substantially filter out frequencies that tend to excite the natural resonant frequency of the electrical conduit.
    Type: Grant
    Filed: December 19, 1994
    Date of Patent: November 11, 1997
    Assignee: Trans-Coil, Inc.
    Inventor: John F. Hibbard