Patents by Inventor James Sigamani

James Sigamani 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: 11121633
    Abstract: A switch-mode DC-DC power converter includes one or more input terminals and output terminals, and a transformer coupled between the input and output terminals. The transformer includes a plurality of winding sets. Each winding set includes a primary winding and a secondary winding magnetically coupled with one another. The primary winding and the secondary winding include the same number of turns. The primary windings of the plurality of winding sets are connected in series and the secondary windings of the plurality of winding sets are connected in parallel. The power converter also includes at least one spacer positioned to separate an adjacent pair of the plurality of winding sets. A magnetic coupling between the adjacent pair of the plurality of winding sets is less than the magnetic coupling between the primary winding and the secondary winding within each winding set.
    Type: Grant
    Filed: November 20, 2019
    Date of Patent: September 14, 2021
    Assignee: Astee International Limited
    Inventor: James Sigamani
  • Publication number: 20210273578
    Abstract: A switch-mode power supply includes a pair of input terminals for receiving an alternating current (AC) or direct current (DC) voltage input from an input power source, a pair of output terminals for supplying a direct current (DC) voltage output to a load, and a three-level LLC circuit coupled between the pair of input terminals and the pair of output terminals. The circuit includes a first switch coupled with a first diode to define a first half-bridge and a second switch coupled with a second diode to define a second half-bridge. The power supply further includes a third switch coupled across the first diode and the second diode to short circuit the first diode and the second diode when the third switch is closed, and a control circuit including a voltage-controlled oscillator (VCO), at least one flip-flop and multiple logic gates to operate the three switches with zero-voltage switching (ZVS).
    Type: Application
    Filed: June 30, 2020
    Publication date: September 2, 2021
    Inventor: James SIGAMANI
  • Publication number: 20210273567
    Abstract: A switch-mode power supply includes a pair of input terminals, a pair of output terminals, and at least four switches coupled in a three-level LLC circuit arrangement between the pair of input terminals and the pair of output terminals. First and second ones of the at least four switches define a first half-bridge and third and fourth ones of the at least four switches define a second half-bridge. The power supply also includes a fifth switch coupled across the second switch and the third switch to short circuit the second switch and the third switch when the fifth switch is closed, and a control circuit. The control circuit includes a voltage-controlled oscillator (VCO) and multiple logic gates and flip-flops coupled to operate the at least four switches with zero-voltage switching (ZVS).
    Type: Application
    Filed: February 28, 2020
    Publication date: September 2, 2021
    Inventor: James SIGAMANI
  • Publication number: 20210273566
    Abstract: A switch-mode power supply includes a pair of input terminals for receiving an alternating current (AC) or direct current (DC) voltage input from an input power source, a pair of output terminals for supplying a direct current (DC) voltage output to a load, and at least four switches coupled in a three-level LLC circuit arrangement between the pair of input terminals and the pair of output terminals. The power supply also includes a voltage doubler power factor correction (PFC) circuit coupled between the pair of input terminals and the three-level LLC circuit, and a control circuit coupled to operate the at least four switches to supply the DC voltage output to the load.
    Type: Application
    Filed: February 28, 2020
    Publication date: September 2, 2021
    Inventor: James SIGAMANI
  • Patent number: 11108329
    Abstract: A switch-mode power supply includes a pair of input terminals for receiving an alternating current (AC) or direct current (DC) voltage input from an input power source, a pair of output terminals for supplying a direct current (DC) voltage output to a load, and at least four switches coupled in a three-level LLC circuit arrangement between the pair of input terminals and the pair of output terminals. The power supply also includes a voltage doubler power factor correction (PFC) circuit coupled between the pair of input terminals and the three-level LLC circuit, and a control circuit coupled to operate the at least four switches to supply the DC voltage output to the load.
    Type: Grant
    Filed: February 28, 2020
    Date of Patent: August 31, 2021
    Assignee: Astec International Limited
    Inventor: James Sigamani
  • Publication number: 20200287467
    Abstract: A switch-mode DC-DC power converter includes one or more input terminals and output terminals, and a transformer coupled between the input and output terminals. The transformer includes a plurality of winding sets. Each winding set includes a primary winding and a secondary winding magnetically coupled with one another. The primary winding and the secondary winding include the same number of turns. The primary windings of the plurality of winding sets are connected in series and the secondary windings of the plurality of winding sets are connected in parallel. The power converter also includes at least one spacer positioned to separate an adjacent pair of the plurality of winding sets. A magnetic coupling between the adjacent pair of the plurality of winding sets is less than the magnetic coupling between the primary winding and the secondary winding within each winding set.
    Type: Application
    Filed: November 20, 2019
    Publication date: September 10, 2020
    Inventor: James SIGAMANI
  • Publication number: 20200286670
    Abstract: A transformer includes a magnetic structure and a set of coils. The magnetic structure includes a top member, a bottom member, and a plurality of legs extending between the top member and the bottom member. The plurality of legs include two outer legs. The set of coils is wound about the two outer legs of the magnetic structure and electrically coupled in series. In other examples, the magnetic structure includes a middle member positioned between the top member and the bottom and extending between the two outer legs. In such examples, a second set of coils is wound about the two outer legs of the magnetic structure and electrically coupled in series. Other example transformers and power converters such as multiphase interleaved power converters having transformers are also disclosed.
    Type: Application
    Filed: March 5, 2019
    Publication date: September 10, 2020
    Inventors: James SIGAMANI, Jonathan Ross Bernardo FAUNI
  • Patent number: 10742123
    Abstract: A switch-mode DC-DC power converter includes one or more input terminals and output terminals, and a transformer coupled between the input and output terminals. The transformer includes a plurality of winding sets. Each winding set includes a primary winding and a secondary winding magnetically coupled with one another. The primary winding and the secondary winding include the same number of turns. The primary windings of the plurality of winding sets are connected in series and the secondary windings of the plurality of winding sets are connected in parallel. The power converter also includes at least one spacer positioned to separate an adjacent pair of the plurality of winding sets. A magnetic coupling between the adjacent pair of the plurality of winding sets is less than the magnetic coupling between the primary winding and the secondary winding within each winding set.
    Type: Grant
    Filed: March 5, 2019
    Date of Patent: August 11, 2020
    Assignee: Astec International Limited
    Inventor: James Sigamani
  • Patent number: 10476393
    Abstract: A DC-DC power converter kit includes a body, a plurality of input connectors, and a plurality of output connectors. The body includes a plurality of inputs configured to couple to one another to form a power converter input, a plurality of outputs configured to couple to one another to form a power converter output, and a plurality of transformers. The power converter output is configured to provide a first output voltage when using a first set of the input connectors and a first output connector, and the power converter output is configured to provide a second output voltage different than the first output voltage when using a second set of the input connectors and a second output connector. Additional example power converter kits, power converters, and methods for adjusting an output voltage are also disclosed.
    Type: Grant
    Filed: November 15, 2016
    Date of Patent: November 12, 2019
    Assignee: Astec International Limited
    Inventor: James Sigamani
  • Patent number: 10224828
    Abstract: A DC-DC power converter includes an input, an output, a transformer, a primary field-effect transistor (FET), and a synchronous rectifier. The synchronous rectifier includes a drain that experiences multiple resonant voltage valleys during each dead-time period of the converter. The converter further includes a synchronous rectifier drive circuit configured to turn on and turn off the synchronous rectifier, and a primary control circuit. The primary control circuit is configured to operate the primary FET in a valley skipping mode, and to transmit a drive signal to the synchronous rectifier drive circuit to turn on the synchronous rectifier during a specified one of the multiple resonant voltage valleys to generate a negative current through the synchronous rectifier. Methods of operating a DC-DC power converter are also disclosed.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: March 5, 2019
    Assignee: Astec International Limited
    Inventors: James Sigamani, Antonio Remetio Soleño, Kenneth Rivera Lazo
  • Patent number: 9906121
    Abstract: A control circuit includes a first integrator circuit corresponding to a first mode and a second integrator circuit corresponding to a second mode. The control circuit is configured to transition control of the power converter between the first mode and the second mode such that one of the first mode and the second mode is a controlling mode for a period of time and the other one of the first mode and the second mode is a non-controlling mode for the period of time, and set an output of the first integrator circuit or the second integrator circuit corresponding to the non-controlling mode to equal an output of the first integrator circuit or the second integrator circuit corresponding to the controlling mode. Other example control circuits, power converters including a control circuit, and methods for controlling a power converter are also disclosed.
    Type: Grant
    Filed: October 8, 2015
    Date of Patent: February 27, 2018
    Assignee: ASTEC INTERNATIONAL LIMITED
    Inventors: Yancy Fontanilla Boncato, James Sigamani, Jonathan Ross Bernardo Fauni
  • Patent number: 9906135
    Abstract: A multiphase DC/DC power converter includes an input, an output, at least a first converter and a second converter coupled in parallel between the input and the output, an inductor coupled to the first and second converters, an output capacitor coupled between the first and second converters and the output, and a control circuit coupled to the first converter and the second converter. The first and second converters each include a power switch. The control circuit is configured to switch the power switches at a frequency with a phase shift therebetween, and to vary the frequency to regulate a voltage at the output. Additionally, the control circuit may be configured to switch power switches at a fixed frequency with substantially no phase shift therebetween during startup of a multiphase DC/DC power converter, and at a variable frequency with a defined phase shift therebetween after startup.
    Type: Grant
    Filed: September 21, 2015
    Date of Patent: February 27, 2018
    Assignee: Astec International Limited
    Inventors: James Sigamani, Vijay Gangadhar Phadke
  • Publication number: 20170155332
    Abstract: A DC-DC power converter kit includes a body, a plurality of input connectors, and a plurality of output connectors. The body includes a plurality of inputs configured to couple to one another to form a power converter input, a plurality of outputs configured to couple to one another to form a power converter output, and a plurality of transformers. The power converter output is configured to provide a first output voltage when using a first set of the input connectors and a first output connector, and the power converter output is configured to provide a second output voltage different than the first output voltage when using a second set of the input connectors and a second output connector. Additional example power converter kits, power converters, and methods for adjusting an output voltage are also disclosed.
    Type: Application
    Filed: November 15, 2016
    Publication date: June 1, 2017
    Inventor: James SIGAMANI
  • Publication number: 20170104407
    Abstract: A control circuit includes a first integrator circuit corresponding to a first mode and a second integrator circuit corresponding to a second mode. The control circuit is configured to transition control of the power converter between the first mode and the second mode such that one of the first mode and the second mode is a controlling mode for a period of time and the other one of the first mode and the second mode is a non-controlling mode for the period of time, and set an output of the first integrator circuit or the second integrator circuit corresponding to the non-controlling mode to equal an output of the first integrator circuit or the second integrator circuit corresponding to the controlling mode. Other example control circuits, power converters including a control circuit, and methods for controlling a power converter are also disclosed.
    Type: Application
    Filed: October 8, 2015
    Publication date: April 13, 2017
    Inventors: Yancy Fontanilla BONCATO, James SIGAMANI, Jonathan Ross Bernardo FAUNI
  • Patent number: 9450496
    Abstract: A multi-stage power converter includes a pre-regulator circuit configured to provide a regulated output voltage, at least one DC/DC converter, and a control circuit coupled to the pre-regulator circuit and the DC/DC converter. The DC/DC converter is configured to provide an output voltage and an output current to a load. The DC/DC converter includes an input, an output, and at least one power switch. The input of the DC/DC converter is coupled to the pre-regulator circuit. The control circuit is configured to regulate the output voltage of the DC/DC converter and vary the regulated output voltage of the pre-regulator circuit as a function of the output current of the DC/DC converter.
    Type: Grant
    Filed: April 11, 2014
    Date of Patent: September 20, 2016
    Assignee: ASTEC INTERNATIONAL LIMITED
    Inventors: James Sigamani, Antonio Remetio Soleño
  • Patent number: 9240724
    Abstract: A multiphase DC/DC power converter includes an input, an output, at least a first converter and a second converter coupled in parallel between the input and the output, an inductor coupled to the first and second converters, an output capacitor coupled between the first and second converters and the output, and a control circuit coupled to the first converter and the second converter. The first and second converters each include a power switch. The control circuit is configured to switch the power switches at a frequency with a phase shift therebetween, and to vary the frequency to regulate a voltage at the output. Additionally, the control circuit may be configured to switch power switches at a fixed frequency with substantially no phase shift therebetween during startup of a multiphase DC/DC power converter, and at a variable frequency with a defined phase shift therebetween after startup.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: January 19, 2016
    Assignee: ASTEC INTERNATIONAL LIMITED
    Inventors: James Sigamani, Vijay Gangadhar Phadke
  • Publication number: 20160013724
    Abstract: A multiphase DC/DC power converter includes an input, an output, at least a first converter and a second converter coupled in parallel between the input and the output, an inductor coupled to the first and second converters, an output capacitor coupled between the first and second converters and the output, and a control circuit coupled to the first converter and the second converter. The first and second converters each include a power switch. The control circuit is configured to switch the power switches at a frequency with a phase shift therebetween, and to vary the frequency to regulate a voltage at the output. Additionally, the control circuit may be configured to switch power switches at a fixed frequency with substantially no phase shift therebetween during startup of a multiphase DC/DC power converter, and at a variable frequency with a defined phase shift therebetween after startup.
    Type: Application
    Filed: September 21, 2015
    Publication date: January 14, 2016
    Inventors: James SIGAMANI, Vijay Gangadhar PHADKE
  • Patent number: 9065325
    Abstract: A control circuit for controlling one or more power switches of a power converter includes a voltage control loop and a current control loop. The control circuit is configured to generate a current reference for the current control loop using the voltage control loop and an AC reference signal. The control circuit is configured to operate in at least a first mode in which a parameter of the voltage control loop is sampled only at every other zero crossing of the AC reference signal and the sampled parameter is used to generate the current reference for the current control loop. The power converter may be an AC-DC converter or a DC-AC converter (i.e., inverter). Alternatively, the voltage control loop may be sampled at every zero crossing of the AC reference signal, and/or more frequently during transient load conditions.
    Type: Grant
    Filed: January 14, 2014
    Date of Patent: June 23, 2015
    Assignee: ASTEC INTERNATIONAL LIMITED
    Inventors: James Sigamani, Yancy Fontanilla Boncato
  • Publication number: 20140307483
    Abstract: A multi-stage power converter includes a pre-regulator circuit configured to provide a regulated output voltage, at least one DC/DC converter, and a control circuit coupled to the pre-regulator circuit and the DC/DC converter. The DC/DC converter is configured to provide an output voltage and an output current to a load. The DC/DC converter includes an input, an output, and at least one power switch. The input of the DC/DC converter is coupled to the pre-regulator circuit. The control circuit is configured to regulate the output voltage of the DC/DC converter and vary the regulated output voltage of the pre-regulator circuit as a function of the output current of the DC/DC converter.
    Type: Application
    Filed: April 11, 2014
    Publication date: October 16, 2014
    Applicant: Astec International Limited
    Inventors: James Sigamani, Antonio Remetio Soleño
  • Patent number: 8861230
    Abstract: A control circuit for controlling one or more power switches of a power converter includes a voltage control loop and a current control loop. The control circuit is configured to generate a current reference for the current control loop using the voltage control loop and an AC reference signal. The control circuit is configured to operate in at least a first mode in which a parameter of the voltage control loop is sampled only at every other zero crossing of the AC reference signal and the sampled parameter is used to generate the current reference for the current control loop. The power converter may be an AC-DC converter or a DC-AC converter (i.e., inverter). Alternatively, the voltage control loop may be sampled at every zero crossing of the AC reference signal, and/or more frequently during transient load conditions.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: October 14, 2014
    Assignee: Astec International Limited
    Inventors: James Sigamani, Yancy Fontanilla Boncato