Patents by Inventor Mahesh Krishnamurthy

Mahesh Krishnamurthy 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).

  • Publication number: 20180367137
    Abstract: A gate driver circuit comprises a sensor, an amplifier, a regulator and a gate driver. The sensor is configured to sense a collector-emitter voltage and includes a first resistor and a second resistor connected in series, a high voltage diode connected between the series connected first and second resistors and a first capacitor connected parallel to the second resistor. The amplifier is configured to amplify a sensor output voltage and includes a non-inverting operational amplifier controlled by means of a plurality of resistors, a voltage follower connected to an output terminal of the non-inverting operational amplifier through a first diode and a third resistor connected across the first diode and the voltage follower. The regulator is configured to regulate a regulator output voltage based on an amplifier voltage. The gate driver is configured to connect/disconnect the regulator output voltage to the base terminal of the BJT.
    Type: Application
    Filed: May 29, 2018
    Publication date: December 20, 2018
    Inventors: Alejandro Pozo Arribas, Mahesh Krishnamurthy
  • Publication number: 20180367078
    Abstract: A method and apparatus for quasi-sensorless adaptive control of a high rotor pole switched-reluctance motor (HRSRM). The method comprises the steps of: applying a voltage pulse to an inactive phase winding and measuring current response in each inactive winding. Motor index pulses are used for speed calculation and to establish a time base. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The apparatus for quasi-sensorless control of a high rotor pole switched-reluctance motor (HRSRM) comprises a switched-reluctance motor having a stator and a rotor, a three-phase inverter controlled by a processor connected to the switched-reluctance motor, a load and a converter.
    Type: Application
    Filed: October 18, 2017
    Publication date: December 20, 2018
    Inventors: Trevor A. Creary, Mahesh Krishnamurthy, Piyush C. Desai, Mark Johnston, Timothy Knodel
  • Publication number: 20180301967
    Abstract: A high rotor pole switched reluctance machine (HRSRM) employs an axial and radial mirroring concept and is represented by a first Multiple Rotor Pole (MRP) formula and second Multiple Stator Pole (MSP) formula. A multiple rotor HRSRM comprises at least two rotors each having a plurality of rotor poles and at least two stators having a plurality of stator poles. The at least two rotors and the at least two stators are positioned about a central axis with the stator placed between the rotors. In other embodiments, the number of stators equals the number of rotors and effectively operate as a single stator and rotor. In yet another embodiment, the effective single stator and rotor type high rotor pole switched reluctance machine is realized as single stator and rotor positioned concentrically around a central axis.
    Type: Application
    Filed: June 18, 2018
    Publication date: October 18, 2018
    Inventors: Mahesh Krishnamurthy, Mark Johnston, Trevor Creary, Piyush Desai
  • Patent number: 10069449
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Grant
    Filed: November 1, 2017
    Date of Patent: September 4, 2018
    Assignee: Software Motor Company
    Inventors: Mahesh Krishnamurthy, Trevor Creary
  • Publication number: 20180191230
    Abstract: A high rotor pole switched reluctance machine (HRSRM) employs an axial and radial mirroring concept and is represented by a first Multiple Rotor Pole (MRP) formula and second Multiple Stator Pole (MSP) formula. A multiple rotor HRSRM comprises at least two rotors each having a plurality of rotor poles and at least two stators having a plurality of stator poles. The at least two rotors and the at least two stators are positioned about a central axis with the stator placed between the rotors. In other embodiments, the number of stators equals the number of rotors and effectively operate as a single stator and rotor. In yet another embodiment, the effective single stator and rotor type high rotor pole switched reluctance machine is realized as single stator and rotor positioned concentrically around a central axis.
    Type: Application
    Filed: March 4, 2018
    Publication date: July 5, 2018
    Inventors: Mahesh Krishnamurthy, Mark Johnston, Trevor Creary, Piyush Desai
  • Patent number: 9960662
    Abstract: A high rotor pole switched reluctance machine (HRSRM) employs an axial and radial mirroring concept and is represented by a first Multiple Rotor Pole (MRP) formula and second Multiple Stator Pole (MSP) formula. A multiple rotor HRSRM comprises at least two rotors each having a plurality of rotor poles and at least one stator having a plurality of stator poles. The at least two rotors and the at least one stator are positioned about a central axis with the stator placed between, and laterally adjacent to the rotors. A multiple stator HRSRM comprises at least two stators having a plurality of stator poles and at least one rotor having a plurality of rotor poles. The at least two stators and at least one rotor are positioned about a central axis with the rotor placed between and laterally adjacent to the stators.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: May 1, 2018
    Assignee: Software Motor Company
    Inventors: Mahesh Krishnamurthy, Mark Johnston, Trevor Creary, Piyush Desai
  • Publication number: 20180088588
    Abstract: A machine vision system having a first camera configured to be coupled to a vehicle, The camera includes an optical stack having a color filter array with a plurality of sections. Each section includes a first white filter portion, a yellow filter portion, a magenta filter portion, and a second white filter portion.
    Type: Application
    Filed: September 22, 2017
    Publication date: March 29, 2018
    Inventors: Lucian ION, Mahesh KRISHNAMURTHY
  • Publication number: 20180069500
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; and estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Application
    Filed: November 1, 2017
    Publication date: March 8, 2018
    Inventors: MAHESH KRISHNAMURTHY, TREVOR CREARY
  • Patent number: 9813006
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; storing the self-inductance value and the first current value for each of the stator phases; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; storing the mutual inductance value and the second current value for each of the stator phases; estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Grant
    Filed: January 23, 2017
    Date of Patent: November 7, 2017
    Assignee: Software Motor Corporation
    Inventors: Mahesh Krishnamurthy, Trevor Creary
  • Publication number: 20170133967
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; storing the self-inductance value and the first current value for each of the stator phases; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; storing the mutual inductance value and the second current value for each of the stator phases; estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Application
    Filed: January 23, 2017
    Publication date: May 11, 2017
    Inventors: MAHESH KRISHNAMURTHY, TREVOR CREARY
  • Patent number: 9553538
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; storing the self-inductance value and the first current value for each of the stator phases; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; storing the mutual inductance value and the second current value for each of the stator phases; estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Grant
    Filed: February 4, 2016
    Date of Patent: January 24, 2017
    Assignee: Software Motor Corporation
    Inventors: Mahesh Krishnamurthy, Trevor Creary
  • Publication number: 20160365780
    Abstract: A high rotor pole switched reluctance machine (HRSRM) employs an axial and radial mirroring concept and is represented by a first Multiple Rotor Pole (MRP) formula and second Multiple Stator Pole (MSP) formula. A multiple rotor HRSRM comprises at least two rotors each having a plurality of rotor poles and at least one stator having a plurality of stator poles. The at least two rotors and the at least one stator are positioned about a central axis with the stator placed between, and laterally adjacent to the rotors. A multiple stator HRSRM comprises at least two stators having a plurality of stator poles and at least one rotor having a plurality of rotor poles. The at least two stators and at least one rotor are positioned about a central axis with the rotor placed between and laterally adjacent to the stators.
    Type: Application
    Filed: February 4, 2016
    Publication date: December 15, 2016
    Inventors: Mahesh Krishnamurthy, Mark Johnston, Trevor Creary, Piyush Desai
  • Publication number: 20160226418
    Abstract: A system and method for reliable control of a high rotor pole switched reluctance machine (HRSRM) utilizing a sensorless reliable control system. The method comprising: energizing at least one of the plurality of stator phases; measuring a first current value and time taken by the first current value to reach a first peak value or preset threshold value of current; determining a self-inductance value; storing the self-inductance value and the first current value for each of the stator phases; measuring a second current value and time taken by an adjacent un-energized stator phase to reach a second peak value of current; determining a mutual inductance value; storing the mutual inductance value and the second current value for each of the stator phases; estimating a rotor position utilizing the self-inductance and mutual inductance values; and controlling the HRSRM based on the estimated rotor position.
    Type: Application
    Filed: February 4, 2016
    Publication date: August 4, 2016
    Inventors: Mahesh Krishnamurthy, Trevor Creary
  • Patent number: 6977530
    Abstract: A sense amplifier pulse shaping circuit maintains a relationship between a sense amplifier enable signal and a sense amplifier equalization enable signal while disabling equalization prior to evaluation and disabling evaluation prior to equalization. In some embodiments of the present invention, a sense amplifier pulse shaper circuit generates a sense amplifier equalization control signal and a sense amplifier enable signal. The sense amplifier equalization control signal has a rising transition effectively earlier than the rising transition of the sense amplifier enable signal. The sense amplifier enable signal has a falling transition effectively earlier than the falling transition of the sense amplifier equalization control signal. The sense amplifier equalization signal is discharged into the sense amplifier enable signal.
    Type: Grant
    Filed: February 4, 2004
    Date of Patent: December 20, 2005
    Assignee: Sun Microsystems, Inc.
    Inventors: Ping Wang, Mahesh Krishnamurthy