Patents by Inventor William A. Drafts

William A. Drafts 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: 5923162
    Abstract: An electric current sensor employing a Hall effect generator to be used in measuring electrical currents flowing in a current carrying conductor including a printed circuit board, an amplifier, a control current source, a toroid core having a gap, a Hall effect generator, and first and second traces configured on the printed circuit board so as to be non-inductive when exposed to the impinging magnetic field concentrated by the toroid core across the gap and across the Hall effect generator. The non-inductive configuration of the first and second traces is composed of a plated through hole electrically coupling the first and second traces to form a loop having a loop area equal to zero that is perpendicular to the directional flow of the impinging magnetic field thereby preventing the generation of unwanted induced voltages in the current sensor.
    Type: Grant
    Filed: April 18, 1997
    Date of Patent: July 13, 1999
    Assignee: Bell Technologies Inc.
    Inventors: William A. Drafts, David E. Barry, Peter Harris
  • Patent number: 5874848
    Abstract: An electric current sensor employing a Hall effect generator and a ferrite substrate to be used in the measuring of electrical currents flowing in a current carrying conductor comprising a toroid core having a first and a second gap, a Hall effect generator, a current source, an amplifier, and a trace configuration positioned on the substrate for electrically coupling the amplifier to the Hall effect generator. The toroid core and ferrite substrate forming the complete magnetic circuit for the flow of the magnetic field. The trace configuration thereby being routed so as to be exposed to the magnetic field in two different impinging directions so to compensate for any unwanted induced voltages from being introduced into the output voltage thereby achieving an improved transient response.
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: February 23, 1999
    Assignee: Bell Technologies, Inc.
    Inventors: William A. Drafts, George V. Grama
  • Patent number: 5416407
    Abstract: An electric current sensor employing a Hall effect generator to be used in measuring electrical currents flowing in an electrical conductor. The sensor comprises an amplifier, a constant current source, a gapped toroid core mounted on the component side of a printed circuit board (PCB), a Hall effect generator extending via its output leads from the PCB into the gap of the toroid core, and an inductive loop positioned at the edge of the gap of the toroid core. The inductive loop itself comprises a simple trace formed on the component side of the PCB together with its plated-through-holes extending from the component of the PCB to the printed circuit (clad) side of the PCB. The PCB inductive loop placed at the edge of the gap of the toroid core and connected in series opposition to the output leads of the Hall effect generator, compensates for the unwanted induced voltages in the output leads of the Hall generator.
    Type: Grant
    Filed: June 11, 1993
    Date of Patent: May 16, 1995
    Assignee: F. W. Bell, Inc.
    Inventor: William A. Drafts