Patents by Inventor John C. Culligan

John C. Culligan 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).

  • Time ratio control circuit for contactor or the like
    Patent number: 4516185
    Abstract: A system for controlling current flow to the actuating coil of a contactor or the like. A solid state switch is provided for gating current flow to the coil, and operated by an oscillator stage. A time delay causes the oscillator to operate at a high duty cycle when power is initially applied, allowing a relatively high current to flow to the contactor coil to operate the contacts. Subsequently the control causes the oscillator to operate at a low duty cycle, wherein the solid state switch passes a significantly lower current flow to the coil to maintain the contacts in position.
    Type: Grant
    Filed: September 30, 1983
    Date of Patent: May 7, 1985
    Assignee: Siemens-Allis, Inc.
    Inventors: John C. Culligan, Frederick A. Stich, Conrad F. Williams