Patents by Inventor Roman Kowalchuk

Roman Kowalchuk 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).

  • Magnetic bubble memory bias magnet arrangement
    Patent number: 4025911
    Abstract: An in-plane magnetic holding field, long known to provide improved operating margins for a magnetic bubble memory during stop-start operation, is produced by unique bias magnet designs each of which provides a constant in-plane bias field in a manner consistent with normal bubble propagation as well as with stop-start operation.
    Type: Grant
    Filed: October 23, 1975
    Date of Patent: May 24, 1977
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Andrew Henry Bobeck, Roman Kowalchuk
  • Reactive coupled drive circuit for magnetic bubble memories
    Patent number: 3934235
    Abstract: The two drive coils commonly used for moving magnetic bubbles in a bubble memory are driven by a pair of reactive-coupled tuned circuits. The tuned circuits are designed to maintain the proper phase relationship between currents in the circuits and to provide periodic refresh pulses once operation is initiated.
    Type: Grant
    Filed: November 4, 1974
    Date of Patent: January 20, 1976
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Andrew Henry Bobeck, Donald Eugene Kish, Roman Kowalchuk