Patents by Inventor Stewart O. Martin

Stewart O. Martin 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 field sensor having a Hall effect device with overlapping flux concentrators
    Patent number: 4692703
    Abstract: An alternating magnetic excitation field is generated in the flux concentrators (11,12) of a Hall effect device, including a Hall element (13), by passing an a.c. current through a coil (14). This alternating field serves to drive the flux concentrators into and out of saturation. In the presence of a d.c. magnetic field and when a Hall current is applied to the Hall element, a second harmonic component is generated in the output voltage of the Hall element (13); the amplitude of the second harmonic component providing a measure of the d.c. magnetic field. In an alternative arrangement (FIG. 4) the flux concentrator means is in loop form rather than in a flat configuration as in FIG. 3.
    Type: Grant
    Filed: February 22, 1985
    Date of Patent: September 8, 1987
    Assignee: Standard Telephones and Cables Public Limited Company
    Inventors: Philip Extance, Roger E. Jones, Stewart O. Martin