Patents by Inventor Robert M. Fraas

Robert M. Fraas 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: 5401329
    Abstract: In the present invention, we describe a generic interchangeable thermophotovoltaic (TPV) receiver assembly that can be incorporated in a variety of large or small TPV generators. Our TPV receiver assembly contains low bandgap TPV cells series connected along a line on a thermally conductive circuit carrier. The circuit carrier is directly bonded to a parallel cooling channel. The cooling channel also supports and cools parallel mirror elements which concentrate infrared energy efficiently to the series connected cell string. The cell interconnections are hidden under the mirror elements. The mirror elements, cooling channel, circuit carrier, and series connected cell string together form a linear TPV receiver assembly with + and - terminals on either end. Identical receiver assemblies can be packed side by side each facing an infrared emitter in a large variety of TPV generator configurations.
    Type: Grant
    Filed: June 2, 1993
    Date of Patent: March 28, 1995
    Assignee: JX Crystals, Inc.
    Inventors: Lewis M. Fraas, Robert M. Fraas
  • Patent number: 5383976
    Abstract: Multiple low bandgap GaSb photovoltaic cell strings are mounted around the perimeter of a cylinder in parallel with the cylinder axis. These cell strings face radially inward and receive infrared (IR) radiation from a ceramic axial emitter and efficiently convert this radiation into DC electric power. Linear reflectors are associated with each cell string and serve to concentrate IR energy into the photovoltaic cells or to return it to the emitter. The ceramic emitter is heated from the inside by hydrocarbon combustion. A uniform temperature along the length of the emitter is maintained by staged addition of fuel in a special burner design. Regenerative air heating is also inherent in the burner design increasing its efficiency. Air for the combustion is supplied by a blower. Sliding contacts to the rotating shaft on the blower can be used for DC to AC conversion. The cell strings are cooled through a compact closed cycle convective liquid cooling loop.
    Type: Grant
    Filed: April 19, 1993
    Date of Patent: January 24, 1995
    Assignee: JX Crystals, Inc.
    Inventors: Robert M. Fraas, Lewis M. Fraas, Jany X. Fraas
  • Patent number: 5312521
    Abstract: Multiple low bandgap Ga.sub.1-x In.sub.x Sb photovoltaic cell strings are mounted around the perimeter of a cylinder parallel to a central cylindrical emitter, or radiator. These cell strings face radially inward to receive infrared (IR) radiation from the emitter, and efficiently convert this radiation into DC electric power. Reflecting surfaces are positioned on either side of each cell string to concentrate most of the IR radiation on the photovoltaic cells and return much of the balance to the emitter. The inside of the emitter is heated by flames from small gas jets from a central burner tube with a jet pattern somewhat similar to that of a gas kitchen stove. A uniform temperature along the length of the emitter is maintained by employing a gas jet hole pattern that produces a staged addition of fuel in a special burner design. Regenerative air heating is employed to increase the flame temperature and avoid large energy losses in the stack gas.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: May 17, 1994
    Inventors: Arthur P. Fraas, Robert M. Fraas