Patents by Inventor Michael Craig Stevens

Michael Craig Stevens 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: 7554316
    Abstract: An inductive power transfer system comprises a primary unit (10), having a primary coil (12) and an electrical drive unit (14) which applies electrical drive signals to the primary coil so as to generate an electromagnetic field. The system also comprises at least one secondary device (30), separable from the primary unit and having a secondary coil (32) which couples with the field when the secondary device is in proximity to the primary unit. A control unit (16) causes a circuit including said primary coil to operate, during a measurement period, in an undriven resonating condition. In this condition the application of the drive signals to the primary coil by the electrical drive unit is suspended so that energy stored in the circuit decays over the course of the period. A decay measurement unit (18) takes one or more measures of such energy decay during the measurement period.
    Type: Grant
    Filed: May 11, 2005
    Date of Patent: June 30, 2009
    Assignee: Access Business Group International LLC
    Inventors: Michael Craig Stevens, Alexander Charles Knill, John Robert Dunton
  • Publication number: 20090134713
    Abstract: An inductive power transfer system comprises a primary unit 10, having a primary coil 12 and an electrical drive unit 14 which applies electrical drive signals to the primary coil so as to generate an electromagnetic field. The system also comprises at least one secondary device 30, separable from the primary unit and having a secondary coil 32 which couples with the field when the secondary device is in proximity to the primary unit. A control unit 16 causes a circuit including said primary coil to operate, during a measurement period, in an undriven resonating condition. In this condition the application of the drive signals to the primary coil by the electrical drive unit is suspended so that energy stored in the circuit decays over the course of the period. A decay measurement unit 18 takes one or more measures of such energy decay during the measurement period.
    Type: Application
    Filed: February 6, 2009
    Publication date: May 28, 2009
    Applicant: ACCESS BUSINESS GROUP INTERNATIONAL LLC
    Inventors: Michael Craig Stevens, Alexander Charles Knill, John Robert Dunton