Patents by Inventor John Alan Schroeder

John Alan Schroeder 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: 6972972
    Abstract: An optically isolated power electronic power conversion circuit that includes an input electrical power source, a heat pipe, a power electronic switch or plurality of interconnected power electronic switches, a mechanism for connecting the switch to the input power source, a mechanism for connecting comprising an interconnecting cable and/or bus bar or plurality of interconnecting cables and/or input bus bars, an optically isolated drive circuit connected to the switch, a heat sink assembly upon which the power electronic switch or switches is mounted, an output load, a mechanism for connecting the switch to the output load, the mechanism for connecting including an interconnecting cable and/or bus bar or plurality of interconnecting cables and/or output bus bars, at least one a fiber optic temperature sensor mounted on the heat sink assembly, at least one fiber optic current sensor mounted on the load interconnection cable and/or output bus bar, at least one fiber optic voltage sensor mounted on the load int
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: December 6, 2005
    Assignee: Airak, Inc.
    Inventors: Paul G. Duncan, John Alan Schroeder
  • Patent number: 6838660
    Abstract: In a preferred embodiment, the invention provides a fiber optic pressure sensor apparatus which includes a light source, a reflective sensor diaphragm movable in accordance with pressure in a medium and an optical fiber coupled to the light source for delivering a first wavefront of light to the reflective sensor diaphragm. The optical fiber has an endface which is separated from the reflective sensor diaphragm by a gap, the endface receiving a second wavefront of light reflected from the reflective sensor diaphragm. The first and second wavefronts constructively and destructively interfere to create a modulated optical signal. A spectrometer is coupled to the optical fiber for converting the optical signal into a series of digital values, and means for analyzing the digital values is provided for obtaining a measurement of the pressure in the medium. An optical coupler is preferably provided for coupling the light source, the optical fiber, and the spectrometer.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: January 4, 2005
    Assignee: Airak, Inc.
    Inventors: Paul Grems Duncan, Sean Michael Christian, John Alan Schroeder
  • Patent number: 6756781
    Abstract: Described are improved transmissive magneto-optical sensors that may be used to determine the magnitude and phase of a magnetic field surrounding a conductor, and when in contact with the conductor, the surface temperature of the conductor. The magneto-optical sensor may be made to be symmetric around the direction of propagation of the internal light, enabling ease of manufacturing as well as automated assembly and calibration. The magneto-optical sensor may also be made to be symmetric about the plane determined by the Faraday rotator material, thus enabling reciprocating optical paths for increased vibration and birefringence immunity. The disclosed sensors preferably include cylindrically symmetrical components, thereby making the sensor readily mass-producible.
    Type: Grant
    Filed: November 15, 2002
    Date of Patent: June 29, 2004
    Assignee: Airak, Inc.
    Inventors: Paul Grems Duncan, John Alan Schroeder
  • Publication number: 20040024937
    Abstract: An optically isolated power electronic power conversion circuit that includes an input electrical power source, a heat pipe, a power electronic switch or plurality of interconnected power electronic switches, a mechanism for connecting the switch to the input power source, a mechanism for connecting comprising an interconnecting cable and/or bus bar or plurality of interconnecting cables and/or input bus bars, an optically isolated drive circuit connected to the switch, a heat sink assembly upon which the power electronic switch or switches is mounted, an output load, a mechanism for connecting the switch to the output load, the mechanism for connecting including an interconnecting cable and/or bus bar or plurality of interconnecting cables and/or output bus bars, at least one a fiber optic temperature sensor mounted on the heat sink assembly, at least one fiber optic current sensor mounted on the load interconnection cable and/or output bus bar, at least one fiber optic voltage sensor mounted on the load int
    Type: Application
    Filed: April 15, 2003
    Publication date: February 5, 2004
    Applicant: Airak, Inc.
    Inventors: Paul G. Duncan, John Alan Schroeder
  • Publication number: 20030146748
    Abstract: Described are improved transmissive magneto-optical sensors that may be used to determine the magnitude and phase of a magnetic field surrounding a conductor, and when in contact with the conductor, the surface temperature of the conductor. The magneto-optical sensor may be made to be symmetric around the direction of propagation of the internal light, enabling ease of manufacturing as well as automated assembly and calibration. The magneto-optical sensor may also be made to be symmetric about the plane determined by the Faraday rotator material, thus enabling reciprocating optical paths for increased vibration and birefringence immunity. The disclosed sensors preferably include cylindrically symmetrical components, thereby making the sensor readily mass-producible.
    Type: Application
    Filed: November 15, 2002
    Publication date: August 7, 2003
    Applicant: Airak, Inc.
    Inventors: Paul Grems Duncan, John Alan Schroeder
  • Publication number: 20030001082
    Abstract: In a preferred embodiment, the invention provides a fiber optic pressure sensor apparatus which includes a light source, a reflective sensor diaphragm movable in accordance with pressure in a medium and an optical fiber coupled to the light source for delivering a first wavefront of light to the reflective sensor diaphragm. The optical fiber has an endface which is separated from the reflective sensor diaphragm by a gap, the endface receiving a second wavefront of light reflected from the reflective sensor diaphragm. The first and second wavefronts constructively and destructively interfere to create a modulated optical signal. A spectrometer is coupled to the optical fiber for converting the optical signal into a series of digital values, and means for analyzing the digital values is provided for obtaining a measurement of the pressure in the medium. An optical coupler is preferably provided for coupling the light source, the optical fiber, and the spectrometer.
    Type: Application
    Filed: June 4, 2001
    Publication date: January 2, 2003
    Inventors: Paul Grems Duncan, Sean Michael Christian, John Alan Schroeder