Patents by Inventor Pritam Das

Pritam Das 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: 12095381
    Abstract: A bidirectional AC power converter, having a front-end comprising parallel sets of three switches in series, which connects multi-phase AC to coupling transformer through a first set of tank circuits, for synchronously bidirectionally converting electrical power between the multi-phase AC and a DC potential, and for converting electrical power between the DC potential to a bipolar electrical signal at a switching frequency, controlled such that two of each parallel set of three switches in series are soft-switched and the other switch is semi-soft switched; the coupling transformer being configured to pass the bipolar electrical power at the switching frequency through a second set of the tank circuits to a synchronous converter, which in turn transfers the electrical power to a secondary system at a frequency different from the switching frequency.
    Type: Grant
    Filed: August 15, 2022
    Date of Patent: September 17, 2024
    Assignee: The Research Foundation for The State University of New York
    Inventors: Kalyan Yenduri, Sunil Dube, Pritam Das
  • Publication number: 20240296991
    Abstract: An integrated matrix transformer for point-of-load converters is provided. The matrix transformer has a smaller surface area and a reduced core volume that lowers core losses. The matrix transformer's winding pattern produces a larger magnetizing inductance which aids in attaining better accuracy for gate pulse generation on the synchronous side of a point-of-load converter and mitigates power reversal issues present in traditional point-of-load converters using traditional matrix transformers. A reduction of circulating current in the primary side is also achieved. The matrix transformer comprises: a plurality of elemental transformers, each elemental transformer comprising a core, primary and secondary, linked through upper and lower members. The elemental transformers are magnetically coupled through the upper and lower members such that a flux induced by primary has a return path through one other core. The primaries are wired in series, and the secondaries in parallel.
    Type: Application
    Filed: February 14, 2024
    Publication date: September 5, 2024
    Inventors: Tuhin Subhra Sasmal, Pritam Das
  • Patent number: 12051397
    Abstract: Systems and methods for audio privacy in network video surveillance systems are described. A video camera may include an image sensor and a microphone to generate a video stream. Responsive to detecting a human speaking condition in the video stream, the audio data may be selectively modified to mask a human voice component of the audio data for storing and/or displaying the surveillance video stream.
    Type: Grant
    Filed: February 16, 2021
    Date of Patent: July 30, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: Shaomin Xiong, Toshiki Hirano, Pritam Das, Ramy Ayad, Rajeev Nagabhirava
  • Publication number: 20240048061
    Abstract: A voltage converter, method for operating a voltage converter, and a controller for a voltage converter is provided. An input stage, comprising a first pair of switches is configured to receive electrical power and generate therefrom an oscillating waveform in a transformer circuit comprising an inductor, the oscillating waveform being associated with an inductor current in the inductor. A synchronous rectifier stage, comprising a second pair of switches, is configured to produce a rectified output voltage from power transferred through the transformer circuit. A controller, producing switch control signals, is configured to operate the first pair of switches in a soft switching mode to produce the oscillating waveform having a switching rate dependent on the rectified output voltage and a switching duty cycle dependent on the inductor current; and synchronously operate the second pair of switches to produce the rectified output voltage.
    Type: Application
    Filed: July 14, 2023
    Publication date: February 8, 2024
    Applicant: The Research Foundation for The State University of New York
    Inventors: Tuhin Subhra Sasmal, Pritam Das
  • Patent number: 11689115
    Abstract: A multilevel stage of a bidirectional AC power converter, comprising: a set of switches in series, a set of capacitors in series, the set of capacitors being in parallel with the set of switches; a number of sets of diodes in series; a center tap along the set of switches in series; and a pair of taps, respectively after the first and before the last switch of the set of switches in series; wherein each node between respective capacitors is connected to a node between respective diodes. A converter first stage for a 3-level converter has 6 switches, two capacitors, and two diodes, with the junction between diodes connected to the junction between capacitors, and the diode legs between switches 2-3 and 4-5. The center tap is between switches 3-4, and the pair of taps between switches 1-2 and 5-6.
    Type: Grant
    Filed: October 4, 2021
    Date of Patent: June 27, 2023
    Assignee: The Research Foundation for The State University o
    Inventors: Kalyan Yenduri, Sunil Dube, Pritam Das, Benson Chan
  • Publication number: 20230005653
    Abstract: A transformer for a power converter, comprising: a first auxiliary subcore, a central subcore, and a second auxiliary subcore, each respective subcore comprising a lower plate, at least one pair of central spacers, and an upper plate, the lower plate, at least one pair of central spacers, and the upper plate of each subcore, being respectively separated by a gap; the first auxiliary subcore and the central subcore being separated by a gap; the second auxiliary subcore and the central subcore being separated by a gap; a primary coil, encircling a first spacer of the first auxiliary subcore and a first spacer of the central subcore; and a secondary coil, encircling a second spacer of the second auxiliary subcore and a second spacer of the central subcore.
    Type: Application
    Filed: July 1, 2022
    Publication date: January 5, 2023
    Inventors: Sunil Dube, Kalyan Yenduri, Pritam Das
  • Publication number: 20220393607
    Abstract: A bidirectional AC power converter, having a front-end comprising parallel sets of three switches in series, which connects multi-phase AC to coupling transformer through a first set of tank circuits, for synchronously bidirectionally converting electrical power between the multi-phase AC and a DC potential, and for converting electrical power between the DC potential to a bipolar electrical signal at a switching frequency, controlled such that two of each parallel set of three switches in series are soft-switched and the other switch is semi-soft switched; the coupling transformer being configured to pass the bipolar electrical power at the switching frequency through a second set of the tank circuits to a synchronous converter, which in turn transfers the electrical power to a secondary system at a frequency different from the switching frequency.
    Type: Application
    Filed: August 15, 2022
    Publication date: December 8, 2022
    Inventors: Kalyan Yenduri, Sunil Dube, Pritam Das
  • Patent number: 11509832
    Abstract: Systems and methods for a low light surveillance system with dual video streams are described. A video camera may include an image sensor and an infrared blocking filter. Responsive to detecting low light conditions, the infrared blocking filter may be disabled and the full spectrum video data from the camera may be sent in one video stream that is processed for user display, such as rendering in gray scale, and another video stream that is used for analytics processing, such as event detection.
    Type: Grant
    Filed: February 16, 2021
    Date of Patent: November 22, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Shaomin Xiong, Pritam Das, Ramy Ayad
  • Patent number: 11418125
    Abstract: A bidirectional AC power converter, having a front-end comprising parallel sets of three switches in series, which connects multi-phase AC to coupling transformer through a first set of tank circuits, for synchronously bidirectionally converting electrical power between the multi-phase AC and a DC potential, and for converting electrical power between the DC potential to a bipolar electrical signal at a switching frequency, controlled such that two of each parallel set of three switches in series are soft-switched and the other switch is semi-soft switched; the coupling transformer being configured to pass the bipolar electrical power at the switching frequency through a second set of the tank circuits to a synchronous converter, which in turn transfers the electrical power to a secondary system at a frequency different from the switching frequency.
    Type: Grant
    Filed: October 23, 2020
    Date of Patent: August 16, 2022
    Assignee: The Research Foundation for The State University of New York
    Inventors: Kalyan Yenduri, Sunil Dube, Pritam Das
  • Publication number: 20220256670
    Abstract: An apparatus method for driving light emitting diodes (LEDs), comprising: receiving an alternating current input; producing a DC current having a voltage with an AC-DC boost power-factor correction stage, having a variable-frequency operation, and a set of switches controlled in dependence on the voltage to limit a peak LED current; and producing an LED drive current with a DC-DC power conversion stage having a set of switches to selectively pulse-width modulate the LEDs to control a brightness, wherein the set of switches in the AC-DC boost power-factor correction stage and the set of switches in the DC-DC power conversion stage are each controlled to switch at zero current.
    Type: Application
    Filed: April 18, 2022
    Publication date: August 11, 2022
    Inventor: Pritam Das
  • Publication number: 20220172700
    Abstract: Systems and methods for audio privacy in network video surveillance systems are described. A video camera may include an image sensor and a microphone to generate a video stream. Responsive to detecting a human speaking condition in the video stream, the audio data may be selectively modified to mask a human voice component of the audio data for storing and/or displaying the surveillance video stream.
    Type: Application
    Filed: February 16, 2021
    Publication date: June 2, 2022
    Inventors: Shaomin Xiong, Toshiki Hirano, Pritam Das, Ramy Ayad, Rajeev Nagabhirava
  • Publication number: 20220174200
    Abstract: Systems and methods for a low light surveillance system with dual video streams are described. A video camera may include an image sensor and an infrared blocking filter. Responsive to detecting low light conditions, the infrared blocking filter may be disabled and the full spectrum video data from the camera may be sent in one video stream that is processed for user display, such as rendering in gray scale, and another video stream that is used for analytics processing, such as event detection.
    Type: Application
    Filed: February 16, 2021
    Publication date: June 2, 2022
    Inventors: Shaomin Xiong, Pritam Das, Ramy Ayad
  • Patent number: 11310883
    Abstract: An apparatus method for driving light emitting diodes (LEDs), comprising: receiving an alternating current input; producing a DC current having a voltage with an AC-DC boost power-factor correction stage, having a variable-frequency operation, and a set of switches controlled in dependence on the voltage to limit a peak LED current; and producing an LED drive current with a DC-DC power conversion stage having a set of switches to selectively pulse-width modulate the LEDs to control a brightness, wherein the set of switches in the AC-DC boost power-factor correction stage and the set of switches in the DC-DC power conversion stage are each controlled to switch at zero current.
    Type: Grant
    Filed: May 14, 2021
    Date of Patent: April 19, 2022
    Assignee: The Research Foundation for The State University of New York
    Inventor: Pritam Das
  • Publication number: 20220109381
    Abstract: A multilevel stage of a bidirectional AC power converter, comprising: a set of switches in series, a set of capacitors in series, the set of capacitors being in parallel with the set of switches; a number of sets of diodes in series; a center tap along the set of switches in series; and a pair of taps, respectively after the first and before the last switch of the set of switches in series; wherein each node between respective capacitors is connected to a node between respective diodes. A converter first stage for a 3-level converter has 6 switches, two capacitors, and two diodes, with the junction between diodes connected to the junction between capacitors, and the diode legs between switches 2-3 and 4-5. The center tap is between switches 3-4, and the pair of taps between switches 1-2 and 5-6.
    Type: Application
    Filed: October 4, 2021
    Publication date: April 7, 2022
    Inventors: Kalyan Yenduri, Sunil Dube, Pritam Das, Benson Chan
  • Publication number: 20210274617
    Abstract: An apparatus method for driving light emitting diodes (LEDs), comprising: receiving an alternating current input; producing a DC current having a voltage with an AC-DC boost power-factor correction stage, having a variable-frequency operation, and a set of switches controlled in dependence on the voltage to limit a peak LED current; and producing an LED drive current with a DC-DC power conversion stage having a set of switches to selectively pulse-width modulate the LEDs to control a brightness, wherein the set of switches in the AC-DC boost power-factor correction stage and the set of switches in the DC-DC power conversion stage are each controlled to switch at zero current.
    Type: Application
    Filed: May 14, 2021
    Publication date: September 2, 2021
    Inventor: Pritam Das
  • Patent number: 11013083
    Abstract: An apparatus method for driving light emitting diodes (LEDs), comprising: receiving an alternating current input; producing a DC current having a voltage with an AC-DC boost power-factor correction stage, having a variable-frequency operation, and a set of switches controlled in dependence on the voltage to limit a peak LED current; and producing an LED drive current with a DC-DC power conversion stage having a set of switches to selectively pulse-width modulate the LEDs to control a brightness, wherein the set of switches in the AC-DC boost power-factor correction stage and the set of switches in the DC-DC power conversion stage are each controlled to switch at zero current.
    Type: Grant
    Filed: May 15, 2020
    Date of Patent: May 18, 2021
    Assignee: The Research Foundation for The State University
    Inventor: Pritam Das
  • Publication number: 20210126550
    Abstract: A bidirectional AC power converter, having a front-end comprising parallel sets of three switches in series, which connects multi-phase AC to coupling transformer through a first set of tank circuits, for synchronously bidirectionally converting electrical power between the multi-phase AC and a DC potential, and for converting electrical power between the DC potential to a bipolar electrical signal at a switching frequency, controlled such that two of each parallel set of three switches in series are soft-switched and the other switch is semi-soft switched; the coupling transformer being configured to pass the bipolar electrical power at the switching frequency through a second set of the tank circuits to a synchronous converter, which in turn transfers the electrical power to a secondary system at a frequency different from the switching frequency.
    Type: Application
    Filed: October 23, 2020
    Publication date: April 29, 2021
    Inventors: Kalyan Yenduri, Sunil Dube, Pritam Das
  • Publication number: 20200375002
    Abstract: An apparatus method for driving light emitting diodes (LEDs), comprising: receiving an alternating current input; producing a DC current having a voltage with an AC-DC boost power-factor correction stage, having a variable-frequency operation, and a set of switches controlled in dependence on the voltage to limit a peak LED current; and producing an LED drive current with a DC-DC power conversion stage having a set of switches to selectively pulse-width modulate the LEDs to control a brightness, wherein the set of switches in the AC-DC boost power-factor correction stage and the set of switches in the DC-DC power conversion stage are each controlled to switch at zero current.
    Type: Application
    Filed: May 15, 2020
    Publication date: November 26, 2020
    Inventor: Pritam Das
  • Publication number: 20110262387
    Abstract: This document relates to methods and materials for treating diseases and disorders that are caused by or associated with amyloid or amyloid-like proteins, such as Alzheimer's disease. For example, methods and materials for using interleukin-6 to reduce or suppress the deposition of A? are provided.
    Type: Application
    Filed: January 28, 2011
    Publication date: October 27, 2011
    Inventors: Pritam Das, Todd E. Golde, Paramita Chakrabarty
  • Publication number: 20110206670
    Abstract: This document provides methods and materials related to anti-amyloid antibodies. For example, anti-amyloid antibodies, methods for making anti-amyloid antibodies, and methods for using an anti-amyloid antibody to treat or prevent an amyloid condition (e.g., AD) are provided.
    Type: Application
    Filed: April 28, 2011
    Publication date: August 25, 2011
    Inventors: Todd E. Golde, Yona R. Levites, Karen R. Jansen-West, Pritam Das, Becky Stodola