Patents by Inventor Fred J Zutavern
Fred J Zutavern 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).
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Publication number: 20190311856Abstract: A ferroelectric opening switch is enabled by controlled polarization switching via nucleation in a ferroelectric material, such as BaTiO3, Pb(Zr,Ti)O3, LiNbO3, LiTaO3, or variants thereof. For example, nucleation sites can be provided by mechanical seeding, grain boundaries, or optical illumination. The invention can be used as an opening switch in large scale pulsed-power systems. However, the switch can also be used in compact pulsed-power systems (e.g., as drivers for high power microwave systems), as passive fault limiters for high voltage dc (HVDC) systems, and/or in other high power applications.Type: ApplicationFiled: April 25, 2016Publication date: October 10, 2019Inventors: Geoffrey L. Brennecka, Steven F. Glover, Gary Pena, Fred J. Zutavern
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Patent number: 10431280Abstract: A ferroelectric opening switch is enabled by controlled polarization switching via nucleation in a ferroelectric material, such as BaTiO3, Pb(Zr,Ti)O3, LiNbO3, LiTaO3, or variants thereof. For example, nucleation sites can be provided by mechanical seeding, grain boundaries, or optical illumination. The invention can be used as an opening switch in large scale pulsed-power systems. However, the switch can also be used in compact pulsed-power systems (e.g., as drivers for high power microwave systems), as passive fault limiters for high voltage dc (HVDC) systems, and/or in other high power applications.Type: GrantFiled: April 25, 2016Date of Patent: October 1, 2019Assignee: National Technology & Engineering Solutions of Sandia, LLCInventors: Geoffrey L. Brennecka, Steven F. Glover, Gary Pena, Fred J. Zutavern
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Patent number: 7173295Abstract: An improved photoconductive semiconductor switch comprises multiple-line optical triggering of multiple, high-current parallel filaments between the switch electrodes. The switch can also have a multi-gap, interdigitated electrode for the generation of additional parallel filaments. Multi-line triggering can increase the switch lifetime at high currents by increasing the number of current filaments and reducing the current density at the contact electrodes in a controlled manner. Furthermore, the improved switch can mitigate the degradation of switching conditions with increased number of firings of the switch.Type: GrantFiled: June 16, 2003Date of Patent: February 6, 2007Assignee: Sandia CorporationInventors: Alan Mar, Fred J. Zutavern, Guillermo Loubriel
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Patent number: 6628404Abstract: Disclosed is a system and method for providing closed-loop control of the heating of a workpiece by an induction heating machine, including generating an acoustic wave in the workpiece with a pulsed laser; optically measuring displacements of the surface of the workpiece in response to the acoustic wave; calculating a sub-surface material property by analyzing the measured surface displacements; creating an error signal by comparing an attribute of the calculated sub-surface material properties with a desired attribute; and reducing the error signal below an acceptable limit by adjusting, in real-time, as often as necessary, the operation of the inductive heating machine.Type: GrantFiled: November 21, 2000Date of Patent: September 30, 2003Assignee: Sandia CorporationInventors: John Bruce Kelley, Wei-Yang Lu, Fred J. Zutavern
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Patent number: 6566636Abstract: A method and system for providing real-time, closed-loop control of the induction hardening process. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, Bsat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).Type: GrantFiled: July 29, 2002Date of Patent: May 20, 2003Assignee: Sandia CorporationInventors: Anthony E. Bentley, John Bruce Kelley, Fred J. Zutavern
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Patent number: 6504859Abstract: The present invention provides a new type of semiconductor light source that can produce a high peak power output and is not injection, e-beam, or optically pumped. The present invention is capable of producing high quality coherent or incoherent optical emission. The present invention is based on current filaments, unlike conventional semiconductor lasers that are based on p-n junctions. The present invention provides a light source formed by an electron-hole plasma inside a current filament. The electron-hole plasma can be several hundred microns in diameter and several centimeters long. A current filament can be initiated optically or with an e-beam, but can be pumped electrically across a large insulating region. A current filament can be produced in high gain photoconductive semiconductor switches. The light source provided by the present invention has a potentially large volume and therefore a potentially large energy per pulse or peak power available from a single (coherent) semiconductor laser.Type: GrantFiled: January 21, 2000Date of Patent: January 7, 2003Assignee: Sandia CorporationInventors: Fred J. Zutavern, Guillermo M. Loubriel, Malcolm T. Buttram, Alan Mar, Wesley D. Helgeson, Martin W. O'Malley, Harold P. Hjalmarson, Albert G. Baca, Weng W. Chow, G. Allen Vawter
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Patent number: 6455825Abstract: A method of monitoring the process of induction heating a workpiece. A miniature magnetic sensor located near the outer surface of the workpiece measures changes in the surface magnetic field caused by changes in the magnetic properties of the workpiece as it heats up during induction heating (or cools down during quenching). A passive miniature magnetic sensor detects a distinct magnetic spike that appears when the saturation field, Bsat, of the workpiece has been exceeded. This distinct magnetic spike disappears when the workpiece's surface temperature exceeds its Curie temperature, due to the sudden decrease in its magnetic permeability. Alternatively, an active magnetic sensor can also be used to measure changes in the resonance response of the monitor coil when the excitation coil is linearly swept over 0-10 MHz, due to changes in the magnetic permeability and electrical resistivity of the workpiece as its temperature increases (or decreases).Type: GrantFiled: November 21, 2000Date of Patent: September 24, 2002Assignee: Sandia CorporationInventors: Anthony E. Bentley, John Bruce Kelley, Fred J. Zutavern
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Patent number: 6248992Abstract: A photoconductive semiconductor switch with tailored doping profile zones beneath and extending laterally from the electrical contacts to the device. The zones are of sufficient depth and lateral extent to isolate the contacts from damage caused by the high current filaments that are created in the device when it is turned on. The zones may be formed by etching depressions into the substrate, then conducting epitaxial regrowth in the depressions with material of the desired doping profile. They may be formed by surface epitaxy. They may also be formed by deep diffusion processes. The zones act to reduce the energy density at the contacts by suppressing collective impact ionization and formation of filaments near the contact and by reducing current intensity at the contact through enhanced current spreading within the zones.Type: GrantFiled: June 18, 1999Date of Patent: June 19, 2001Assignee: Sandia CorporationInventors: Albert G. Baca, Guillermo M. Loubriel, Alan Mar, Fred J Zutavern, Harold P. Hjalmarson, Andrew A. Allerman, Thomas E. Zipperian, Martin W. O'Malley, Wesley D. Helgeson, Gary J. Denison, Darwin J. Brown, Charles T. Sullivan, Hong Q. Hou
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Patent number: 5804815Abstract: A high gain, optically triggered, photoconductive semiconductor switch (PCSS) implemented in GaAs as a reverse-biased pin structure with a passivation layer above the intrinsic GaAs substrate in the gap between the two electrodes of the device. The reverse-biased configuration in combination with the addition of the passivation layer greatly reduces surface current leakage that has been a problem for prior PCSS devices and enables employment of the much less expensive and more reliable DC charging systems instead of the pulsed charging systems that needed to be used with prior PCSS devices.Type: GrantFiled: July 5, 1996Date of Patent: September 8, 1998Assignee: Sandia CorporationInventors: Guillermo M. Loubriel, Albert G. Baca, Fred J. Zutavern