Patents by Inventor Mark J. Calahan

Mark J. Calahan 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: 6040676
    Abstract: Passive electronic damping apparatus for a step motor of the type having a number of phase windings, comprising: a respective transconductance amplifier coupled to each phase winding for producing a phase drive current in the winding in response to a position command; each transconductance amplifier exhibiting an output impedance characteristic; and a circuit for changing the amplifier output impedance to effect motor damping.
    Type: Grant
    Filed: January 22, 1997
    Date of Patent: March 21, 2000
    Assignee: Parker-Hannifin Corporation
    Inventors: Jack Nordquist, Mark J. Calahan, Timothy J. Damiano, Christopher M. Botka