Patents by Inventor David M. Messersmith

David M. Messersmith 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: 20210319967
    Abstract: A device includes an armature, a coil, and a circuit. The armature is configured to move between a close position that electrically couples the armature to a contact and an open position that is not electrically coupled to the contact. The coil is configured to release a voltage configured to de-magnetize the coil, thereby causing the armature to move from the close position to the open position. The circuit is configured to provide reverse driving current to the coil during a period of time when the armature moves from the close position to the open position.
    Type: Application
    Filed: April 9, 2020
    Publication date: October 14, 2021
    Inventors: ANDREW E. CARLSON, KYLE B. ADKINS, DAVID M. MESSERSMITH
  • Patent number: 11114842
    Abstract: A component includes first and second switches in series and connected between a power source and a coil of contacts of a safety relay. A first controller controls the first switch with a close signal that closes the first switch or a first PWM signal that opens and closes the first switch on each PWM cycle. A second controller controls the second switch with a close signal that closes the second switch or a second PWM signal that opens and closes the second switch on each PWM cycle. A PWM sensing circuit connected to the coil sends a sensed PWM signal to an input of the first and second controllers. The first controller sends the first PWM signal while the second controller sends a close signal and vice-versa. The controllers verify that the received PWM signal matches the sent PWM signal.
    Type: Grant
    Filed: May 27, 2020
    Date of Patent: September 7, 2021
    Assignee: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Yanbin Zhang, Yutao Wang, David M. Messersmith, David B. Berman
  • Patent number: 10958062
    Abstract: Current transformer circuit systems and methods dynamically switch a load. The current transformer circuit includes a current source circuit including at least one current transformer to produce a current output wave. A burden circuit includes at least one burden resistor and a voltage sensor, at least a portion of the current output wave to be passed through the burden resistor, and the voltage sensor to sense a voltage across the respective at least one burden resistor. A switch circuit includes at least one switch, the switch circuit coupled to the burden circuit. A microcontroller circuit includes a microcontroller, the microcontroller circuit coupled to a power circuit and the switch circuit, the microcontroller being configured to control the switch circuit to dynamically switch a secondary loading of the at least one current transformer between the burden resistor and a low resistance load.
    Type: Grant
    Filed: November 13, 2018
    Date of Patent: March 23, 2021
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Andrew E Carlson, Daniel J Bolda, Joseph A Johnson, David M Messersmith
  • Publication number: 20200153227
    Abstract: Current transformer circuit systems and methods dynamically switch a load. The current transformer circuit includes a current source circuit including at least one current transformer to produce a current output wave. A burden circuit includes at least one burden resistor and a voltage sensor, at least a portion of the current output wave to be passed through the burden resistor, and the voltage sensor to sense a voltage across the respective at least one burden resistor. A switch circuit includes at least one switch, the switch circuit coupled to the burden circuit. A microcontroller circuit includes a microcontroller, the microcontroller circuit coupled to a power circuit and the switch circuit, the microcontroller being configured to control the switch circuit to dynamically switch a secondary loading of the at least one current transformer between the burden resistor and a low resistance load.
    Type: Application
    Filed: November 13, 2018
    Publication date: May 14, 2020
    Inventors: Andrew E. Carlson, Daniel J. Bolda, Joseph A. Johnson, David M. Messersmith
  • Patent number: 9880223
    Abstract: A method of estimating stator resistance of an induction motor is provided. The method includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents.
    Type: Grant
    Filed: June 3, 2014
    Date of Patent: January 30, 2018
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: David M. Messersmith, Douglas J. Bader, Haihui Lu, Thomas A. Nondahl, Zhenhuan Yuan
  • Publication number: 20140285230
    Abstract: A method of estimating stator resistance of an induction motor is provided. The method includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents.
    Type: Application
    Filed: June 3, 2014
    Publication date: September 25, 2014
    Inventors: David M. Messersmith, Douglas J. Bader, Haihui Lu, Thomas A. Nondahl, Zhenhuan Yuan
  • Patent number: 8742767
    Abstract: A method of estimating stator resistance of an induction motor includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents.
    Type: Grant
    Filed: November 3, 2009
    Date of Patent: June 3, 2014
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: David M. Messersmith, Douglas J. Bader, Haihui Lu, Thomas A. Nondahl, Zhenhuan Yuan
  • Patent number: 8547050
    Abstract: Systems, methods, and devices are disclosed, including an induction-motor controller having a phase path; a solid-state switch interposed on the phase path; and a controller coupled to the solid-state switch. In certain embodiments, the controller is configured to switch the solid-state switch so that the solid-state switch is conductive during a conduction angle of a cycle of an incoming AC power waveform conveyed by the phase path, calculate the conduction angle based on a generally sinusoidal reference value that has a frequency lower than a frequency of the incoming AC power waveform, and adjust the generally sinusoidal reference value based on a value indicative of flux in a load coupled to the phase path.
    Type: Grant
    Filed: May 17, 2012
    Date of Patent: October 1, 2013
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Haihui Lu, David M. Messersmith, Thomas A. Nondahl
  • Patent number: 8519662
    Abstract: The subject matter disclosed herein describes a system for controlling torque in a soft starter. In particular, torque ripple is reduced when transitioning between two different operating modes of a soft starter. A soft starter may include a first operating mode, designed for improved performance during low-speed operation of a motor, and a second operating mode, designed for improved performance during high-speed operation of the motor. However, transitioning between two different operating modes may result in significant transient currents in the motor, which, in turn, produce torque in the motor. The system described herein reduces this transient torque production in the motor.
    Type: Grant
    Filed: May 26, 2010
    Date of Patent: August 27, 2013
    Assignee: Rockwell Technologies, Inc.
    Inventors: Haihui Lu, David M. Messersmith
  • Publication number: 20120223668
    Abstract: Systems, methods, and devices are disclosed, including an induction-motor controller having a phase path; a solid-state switch interposed on the phase path; and a controller coupled to the solid-state switch. In certain embodiments, the controller is configured to switch the solid-state switch so that the solid-state switch is conductive during a conduction angle of a cycle of an incoming AC power waveform conveyed by the phase path, calculate the conduction angle based on a generally sinusoidal reference value that has a frequency lower than a frequency of the incoming AC power waveform, and adjust the generally sinusoidal reference value based on a value indicative of flux in a load coupled to the phase path.
    Type: Application
    Filed: May 17, 2012
    Publication date: September 6, 2012
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Haihui Lu, David M. Messersmith, Thomas A. Nondahl
  • Patent number: 8203304
    Abstract: Systems, methods, and devices are disclosed, including an induction-motor controller having a phase path; a solid-state switch interposed on the phase path; and a controller coupled to the solid-state switch. In certain embodiments, the controller is configured to switch the solid-state switch so that the solid-state switch is conductive during a conduction angle of a cycle of an incoming AC power waveform conveyed by the phase path, calculate the conduction angle based on a generally sinusoidal reference value that has a frequency lower than a frequency of the incoming AC power waveform, and adjust the generally sinusoidal reference value based on a value indicative of flux in a load coupled to the phase path.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: June 19, 2012
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Haihui Lu, David M. Messersmith, Thomas A. Nondahl
  • Patent number: 8138709
    Abstract: Systems, methods, and devices are disclosed, including an induction-motor controller that has a motor controller configured to receive alternating current (AC) power with a voltage that varies generally sinusoidally and transmit the AC power during a conduction angle of a cycle of the AC power. In some embodiments, the conduction angle varies generally sinusoidally at a lower frequency than the AC power, and the motor controller may be configured to not transmit the AC power outside of the conduction angle.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: March 20, 2012
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: David M. Messersmith, John Herman Blakely
  • Publication number: 20110291596
    Abstract: The subject matter disclosed herein describes a system for controlling torque in a soft starter. In particular, torque ripple is reduced when transitioning between two different operating modes of a soft starter. A soft starter may include a first operating mode, designed for improved performance during low-speed operation of a motor, and a second operating mode, designed for improved performance during high-speed operation of the motor. However, transitioning between two different operating modes may result in significant transient currents in the motor, which, in turn, produce torque in the motor. The system described herein reduces this transient torque production in the motor.
    Type: Application
    Filed: May 26, 2010
    Publication date: December 1, 2011
    Inventors: Haihui Lu, David M. Messersmith
  • Publication number: 20110102012
    Abstract: A method of estimating stator resistance of an induction motor is provided. The method includes applying voltage pulses through two phase paths of the motor for a plurality of electrical cycles to inject current in the motor, wherein the voltage pulses are applied until rotor flux of the motor is substantially stabilized and measuring stator voltage and stator current in response to the applied voltage pulses for each of the plurality of electrical cycles. The method also includes calculating the stator resistance based upon the measured stator voltages and the stator currents.
    Type: Application
    Filed: November 3, 2009
    Publication date: May 5, 2011
    Applicant: Rockwell Automation Technologies, Inc.
    Inventors: David M. Messersmith, Douglas J. Bader, Haihui Lu, Thomas A. Nondahl, Zhenhuan Yuan
  • Patent number: 7672096
    Abstract: An improved switching apparatus and method are disclosed. In at least some embodiments, the apparatus includes first and second ports, a first switching device such as a contactor coupled between the ports, and a second switching device coupled in parallel with the contactor between the ports, where the second switching device can be or include a solid-state semiconductor device. The second switching device is operated to become conductive at a first time prior to a second time when the contactor switches between a conductive state and a non-conductive state, and remains conductive up to a third time subsequent to the second time. In at least some further embodiments, the apparatus also includes one or both of a voltage sensing capability and a current sensing capability and switches the second switching device to become conductive based upon voltage and/or current information.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: March 2, 2010
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: David M. Messersmith, Thomas A. Nondahl
  • Patent number: 7538507
    Abstract: Control systems and speed estimation systems are presented having a transient-based speed estimation system that provides a rotor speed estimate based on a measured speed-related motor transient signal, and a transient excitation system which selectively modifies at least one switch control signal to excite the measured motor transient.
    Type: Grant
    Filed: April 28, 2007
    Date of Patent: May 26, 2009
    Assignee: Rockwell International Technologies, Inc.
    Inventors: Haihui Lu, Thomas A. Nondahl, David M. Messersmith
  • Publication number: 20090058351
    Abstract: Systems, methods, and devices are disclosed, including an induction-motor controller that has a motor controller configured to receive alternating current (AC) power with a voltage that varies generally sinusoidally and transmit the AC power during a conduction angle of a cycle of the AC power. In some embodiments, the conduction angle varies generally sinusoidally at a lower frequency than the AC power, and the motor controller may be configured to not transmit the AC power outside of the conduction angle.
    Type: Application
    Filed: August 31, 2007
    Publication date: March 5, 2009
    Inventors: David M. Messersmith, John Herman Blakely
  • Publication number: 20090058341
    Abstract: Systems, methods, and devices are disclosed, including an induction-motor controller having a phase path; a solid-state switch interposed on the phase path; and a controller coupled to the solid-state switch. In certain embodiments, the controller is configured to switch the solid-state switch so that the solid-state switch is conductive during a conduction angle of a cycle of an incoming AC power waveform conveyed by the phase path, calculate the conduction angle based on a generally sinusoidal reference value that has a frequency lower than a frequency of the incoming AC power waveform, and adjust the generally sinusoidal reference value based on a value indicative of flux in a load coupled to the phase path.
    Type: Application
    Filed: August 31, 2007
    Publication date: March 5, 2009
    Inventors: Haihui Lu, David M. Messersmith, Thomas A. Nondahl
  • Publication number: 20080094771
    Abstract: An improved switching apparatus and method are disclosed. In at least some embodiments, the apparatus includes first and second ports, a first switching device such as a contactor coupled between the ports, and a second switching device coupled in parallel with the contactor between the ports, where the second switching device can be or include a solid-state semiconductor device. The second switching device is operated to become conductive at a first time prior to a second time when the contactor switches between a conductive state and a non-conductive state, and remains conductive up to a third time subsequent to the second time. In at least some further embodiments, the apparatus also includes one or both of a voltage sensing capability and a current sensing capability and switches the second switching device to become conductive based upon voltage and/or current information.
    Type: Application
    Filed: September 29, 2006
    Publication date: April 24, 2008
    Inventors: David M. Messersmith, Thomas A. Nondahl
  • Publication number: 20070247099
    Abstract: Control systems and speed estimation systems are presented having a transient-based speed estimation system that provides a rotor speed estimate based on a measured speed-related motor transient signal, and a transient excitation system which selectively modifies at least one switch control signal to excite the measured motor transient.
    Type: Application
    Filed: April 28, 2007
    Publication date: October 25, 2007
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Haihui Lu, Thomas A. Nondahl, David M. Messersmith