Patents by Inventor Davood B. Motlagh

Davood B. Motlagh 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).

  • Ballast shut-down circuit responsive to an unbalanced load condition in a single lamp ballast or in either lamp of a two-lamp ballast
    Patent number: 5930126
    Abstract: An abnormal or unbalanced load operating condition is detected in a single lamp ballast circuit or in either lamp of a two-lamp ballast circuit by feedback voltage signals that are proportional to the flow of current through the cathodes of each lamp. The analog feedback signals are combined algebraically by a summing circuit that produces a null (zero) value corresponding with normal lamp operation, and produces a non-zero value in response to abnormal cathode current flow. The non-zero value is compared with the reference value to generate a shut-down signal. In one embodiment, the cathode currents are sensed by primary windings of a toroid transformer, and the feedback signals are the magnetic flux components that are generated in response to cathode current flow through the current sensing windings.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: July 27, 1999
    Assignee: The Genlyte Group Incorporated
    Inventors: Raymond T. Griffin, Davood B. Motlagh
  • Ballast shut-down circuit responsive to an unbalanced load condition in a single lamp ballast or in either lamp of a two-lamp ballast
    Patent number: 5636111
    Abstract: An abnormal or unbalanced load operating condition is detected in a single lamp ballast circuit or in either lamp of a two-lamp ballast circuit by feedback voltage signals that are proportional to the flow of current through the cathodes of each lamp. The analog feedback signals are combined algebraically by a summing circuit that produces a null (zero) value corresponding with normal lamp operation, and produces a non-zero value in response to abnormal cathode current flow. The non-zero value is compared with the reference value to generate a shut-down signal. In one embodiment, the cathode currents are sensed by primary windings of a toroid transformer, and the feedback signals are the magnetic flux components that are generated in response to cathode current flow through the current sensing windings.
    Type: Grant
    Filed: March 26, 1996
    Date of Patent: June 3, 1997
    Assignee: The Genlyte Group Incorporated
    Inventors: Raymond T. Griffin, Davood B. Motlagh