Patents by Inventor Keith Johnston

Keith Johnston 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: 11894805
    Abstract: Devices for reducing the open circuit voltages of solar systems are described. In one embodiment, a solar system includes a string of a plurality of solar modules having an open circuit voltage. The solar system also includes a device for reducing the open circuit voltage of the string of the plurality of solar modules during an open circuit configuration.
    Type: Grant
    Filed: October 7, 2016
    Date of Patent: February 6, 2024
    Assignee: Enphase Energy, Inc.
    Inventors: Steven M. Kraft, Kevin Fischer, Greg Beardsworth, Zachary S. Judkins, Keith Johnston
  • Patent number: 9927827
    Abstract: A photovoltaic (PV) system can include one or more trackers that each includes a plurality of rows of PV collection devices. The rows of PV collection devices can be electrically independent from one another.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: March 27, 2018
    Assignee: SunPower Corporation
    Inventors: Keith Johnston, Nicholas Ford
  • Patent number: 9923374
    Abstract: A photovoltaic system includes solar cells and an inverter configured to convert direct current generated by the solar cells to alternating current. The photovoltaic system includes a maximum power point (MPP) tracking module configured to perform MPP tracking for the photovoltaic system. The MPP tracking module is configured to detect shading of the solar cells and to modify its MPP tracking to prevent tracking of local MPPs. The MPP tracking module may be incorporated in the inverter.
    Type: Grant
    Filed: June 14, 2016
    Date of Patent: March 20, 2018
    Assignee: SunPower Corporation
    Inventors: Zachary S. Judkins, Keith Johnston
  • Patent number: 9735729
    Abstract: A photovoltaic string may include an open circuit voltage limiter that conducts current in one direction to provide a limiter voltage less than an open circuit voltage of the photovoltaic string, and that conducts current in the other direction. One or more open circuit voltage limiters may be connected across the photovoltaic string or across selected groups of solar cells of the photovoltaic string. The limiter voltage may be greater than a maximum power point voltage but less than the open circuit voltage of the photovoltaic string.
    Type: Grant
    Filed: October 15, 2015
    Date of Patent: August 15, 2017
    Assignee: SunPower Corporation
    Inventors: Keith Johnston, Zachary S. Judkins
  • Patent number: 9710005
    Abstract: A photovoltaic (PV) system can include strings of PV collection devices. A positive parallel bus can be coupled to positive terminals of first and second strings and a negative parallel bus can be coupled to negative terminals of first and second strings.
    Type: Grant
    Filed: October 31, 2014
    Date of Patent: July 18, 2017
    Assignee: SunPower Corporation
    Inventors: Keith Johnston, Nicholas Ford
  • Patent number: 9685573
    Abstract: Arrangements of diodes and heat spreaders for solar modules are described. For example, a solar module may include a backsheet with a low profile, surface-mount diode disposed above the backsheet. A pair of ribbon interconnects is coupled to the low profile, surface-mount diode and may penetrate the backsheet.
    Type: Grant
    Filed: October 21, 2013
    Date of Patent: June 20, 2017
    Assignee: SUNPOWER CORPORATION
    Inventors: Keith Johnston, Ryan Linderman, Lewis Abra, Matthew Dawson
  • Publication number: 20170025995
    Abstract: Devices for reducing the open circuit voltages of solar systems are described. In one embodiment, a solar system includes a string of a plurality of solar modules having an open circuit voltage. The solar system also includes a device for reducing the open circuit voltage of the string of the plurality of solar modules during an open circuit configuration.
    Type: Application
    Filed: October 7, 2016
    Publication date: January 26, 2017
    Inventors: Steven M. Kraft, Kevin Fischer, Greg Beardsworth, Zachary S. Judkins, Keith Johnston
  • Patent number: 9537036
    Abstract: Interconnects for optoelectronic devices are described. For example, an interconnect for an optoelectronic device includes an interconnect body having an inner surface, an outer surface, a first end, and a second end. A plurality of bond pads is coupled to the inner surface of the interconnect body, between the first and second ends. A stress relief feature is disposed in the interconnect body. The stress relief feature includes a slot disposed entirely within the interconnect body without extending through to the inner surface, without extending through to the outer surface, without extending through to the first end, and without extending through to the second end of the interconnect body.
    Type: Grant
    Filed: June 13, 2014
    Date of Patent: January 3, 2017
    Assignee: SunPower Corporation
    Inventors: Ryan Linderman, Keith Johnston, Thomas Phu, Matthew Dawson
  • Publication number: 20160365733
    Abstract: A photovoltaic system includes solar cells and an inverter configured to convert direct current generated by the solar cells to alternating current. The photovoltaic system includes a maximum power point (MPP) tracking module configured to perform MPP tracking for the photovoltaic system. The MPP tracking module is configured to detect shading of the solar cells and to modify its MPP tracking to prevent tracking of local MPPs. The MPP tracking module may be incorporated in the inverter.
    Type: Application
    Filed: June 14, 2016
    Publication date: December 15, 2016
    Applicant: SunPower Corporation
    Inventors: Zachary S. JUDKINS, Keith JOHNSTON
  • Patent number: 9472691
    Abstract: Devices for reducing the open circuit voltages of solar systems are described. In one embodiment, a solar system includes a string of a plurality of solar modules having an open circuit voltage. The solar system also includes a device for reducing the open circuit voltage of the string of the plurality of solar modules during an open circuit configuration.
    Type: Grant
    Filed: August 25, 2011
    Date of Patent: October 18, 2016
    Assignee: SunPower Corporation
    Inventors: Steven M. Kraft, Kevin Fischer, Greg Beardsworth, Zachary S. Judkins, Keith Johnston
  • Publication number: 20160284909
    Abstract: Solar cells can include a plurality of sub-cells that include a singulated and physically separated semiconductor portion such that adjacent ones of the singulated and physically separated semiconductor portions can have a groove therebetween. The solar cells can include a metallization structure that couples ones of the plurality of sub-cells. An interconnect structure can couple adjacent ones of the solar cells.
    Type: Application
    Filed: March 27, 2015
    Publication date: September 29, 2016
    Inventors: Gabriel Harley, Seung Bum Rim, Keith Johnston, Matthieu Minault Reich
  • Patent number: 9397611
    Abstract: A photovoltaic system includes solar cells and an inverter configured to convert direct current generated by the solar cells to alternating current. The photovoltaic system includes a maximum power point (MPP) tracking module configured to perform MPP tracking for the photovoltaic system. The MPP tracking module is configured to detect shading of the solar cells and to modify its MPP tracking to prevent tracking of local MPPs. The MPP tracking module may be incorporated in the inverter.
    Type: Grant
    Filed: March 27, 2012
    Date of Patent: July 19, 2016
    Assignee: SunPower Corporation
    Inventors: Zachary S. Judkins, Keith Johnston
  • Publication number: 20160079914
    Abstract: A photovoltaic (PV) system is disclosed. The PV system can include a first and a second tracker that includes a first and a second plurality of PV collection devices. The PV system can include a first motor configured to adjust an angle of the first tracker. The PV system can include an inverter coupled to an output of the first plurality of PV collection devices. The inverter can include a first local controller comprising control circuitry configured to control the first motor. In an example, the inverter can be a string inverter. In one example, the inverter can a block inverter coupled to an output of the first and second plurality of PV collection devices. The PV system can also include a power collection unit, where the power collection unit can be coupled to the first plurality of PV collection devices and include the first local controller.
    Type: Application
    Filed: September 14, 2015
    Publication date: March 17, 2016
    Inventors: Junbo Wu, Keith Johnston, Chen-An Chen, Zachary S. Judkins
  • Publication number: 20160048151
    Abstract: A photovoltaic (PV) system can include one or more trackers that each includes a plurality of rows of PV collection devices. The rows of PV collection devices can be electrically independent from one another.
    Type: Application
    Filed: October 31, 2014
    Publication date: February 18, 2016
    Inventors: Keith Johnston, Nicholas Ford
  • Publication number: 20160049791
    Abstract: A photovoltaic (PV) system can include strings of PV collection devices. A positive parallel bus can be coupled to positive terminals of first and second strings and a negative parallel bus can be coupled to negative terminals of first and second strings.
    Type: Application
    Filed: October 31, 2014
    Publication date: February 18, 2016
    Inventors: Keith Johnston, Nicholas Ford
  • Publication number: 20160036380
    Abstract: A photovoltaic string may include an open circuit voltage limiter that conducts current in one direction to provide a limiter voltage less than an open circuit voltage of the photovoltaic string, and that conducts current in the other direction. One or more open circuit voltage limiters may be connected across the photovoltaic string or across selected groups of solar cells of the photovoltaic string. The limiter voltage may be greater than a maximum power point voltage but less than the open circuit voltage of the photovoltaic string.
    Type: Application
    Filed: October 15, 2015
    Publication date: February 4, 2016
    Applicant: SunPower Corporation
    Inventors: Keith JOHNSTON, Zachary S. JUDKINS
  • Patent number: 9190839
    Abstract: A photovoltaic string may include an open circuit voltage limiter that conducts current in one direction to provide a limiter voltage less than an open circuit voltage of the photovoltaic string, and that conducts current in the other direction. One or more open circuit voltage limiters may be connected across the photovoltaic string or across selected groups of solar cells of the photovoltaic string. The limiter voltage may be greater than a maximum power point voltage but less than the open circuit voltage of the photovoltaic string.
    Type: Grant
    Filed: December 5, 2013
    Date of Patent: November 17, 2015
    Assignee: SunPower Corporation
    Inventors: Keith Johnston, Zachary S. Judkins
  • Publication number: 20150037460
    Abstract: The invention process provides a novel process of making cheese comprising the production of a coagulum which is caused to disaggregate into small curd particles in an in-line continuous flow process, separation of the curd particles from the whey and subsequent heating and mechanical working of the curd particles into a cheese mass.
    Type: Application
    Filed: October 16, 2014
    Publication date: February 5, 2015
    Inventors: Keith Johnston, Allan Main, Peter Dudley Elston, Peter Aaron Munro, Robert J. Buwalda
  • Publication number: 20140352761
    Abstract: Optoelectronic devices with bypass diodes are described. An optoelectronic device includes a bypass diode, a heat spreader unit disposed above, and extending over, the bypass diode, and a heat sink disposed above the heat spreader unit. Another optoelectronic device includes a bypass diode, a heat spreader unit disposed above, but not extending over, the bypass diode, and a heat sink disposed above the heat spreader unit.
    Type: Application
    Filed: August 18, 2014
    Publication date: December 4, 2014
    Inventors: Ryan Linderman, Doug Rose, Nicholas Boitnott, Keith Johnston, David B. DeGraaff
  • Publication number: 20140291852
    Abstract: Interconnects for optoelectronic devices are described. For example, an interconnect for an optoelectronic device includes an interconnect body having an inner surface, an outer surface, a first end, and a second end. A plurality of bond pads is coupled to the inner surface of the interconnect body, between the first and second ends. A stress relief feature is disposed in the interconnect body. The stress relief feature includes a slot disposed entirely within the interconnect body without extending through to the inner surface, without extending through to the outer surface, without extending through to the first end, and without extending through to the second end of the interconnect body.
    Type: Application
    Filed: June 13, 2014
    Publication date: October 2, 2014
    Inventors: Ryan Linderman, Keith Johnston, Thomas Phu, Matthew Dawson