Patents by Inventor Malakondaiah Naidu

Malakondaiah Naidu 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: 7543687
    Abstract: A piston damper assembly includes a piston damper and a relative position sensor. The piston damper includes a damper body and a piston rod. The piston rod is axially movable within the damper body. The relative position sensor includes an axially-extending magnetic core, an excitation coil, and a position-sensing coil. The axially-extending magnetic core is movable with the piston rod, is located outside the damper body, and has first and second protrusions extending toward the damper body. The excitation coil is wound around the first protrusion, and the position-sensing coil is wound around the second protrusion. A piston-damper dust tube subassembly includes an axially-extending piston-damper dust tube and a relative position sensor. The relative position sensor includes an axially-extending magnetic core, an excitation coil, and a position-sensing coil. The axially-extending magnetic core is attached to the dust tube and has first and second protrusions.
    Type: Grant
    Filed: March 16, 2006
    Date of Patent: June 9, 2009
    Assignee: Delphi Technologies, Inc.
    Inventors: Malakondaiah Naidu, Thomas W. Nehl
  • Publication number: 20070215420
    Abstract: A piston damper assembly includes a piston damper and a relative position sensor. The piston damper includes a damper body and a piston rod. The piston rod is axially movable within the damper body. The relative position sensor includes an axially-extending magnetic core, an excitation coil, and a position-sensing coil. The axially-extending magnetic core is movable with the piston rod, is located outside the damper body, and has first and second protrusions extending toward the damper body. The excitation coil is wound around the first protrusion, and the position-sensing coil is wound around the second protrusion. A piston-damper dust tube subassembly includes an axially-extending piston-damper dust tube and a relative position sensor. The relative position sensor includes an axially-extending magnetic core, an excitation coil, and a position-sensing coil. The axially-extending magnetic core is attached to the dust tube and has first and second protrusions.
    Type: Application
    Filed: March 16, 2006
    Publication date: September 20, 2007
    Inventors: Malakondaiah Naidu, Thomas Nehl
  • Patent number: 7205772
    Abstract: An arc fault detector includes a shunt resistor deployed in a protected circuit, an arc discriminator sensing voltages across the shunt resistor and producing an arc indication deduced from current variations associated with parallel and series arc faults, a signal transformer buffering the arc detection signal and producing a pulse, a switch transient detector sensing a voltage differential across load switches and producing a pulsed switch transient signal when the voltage differential across load switches exceeds a reference value, a line interrupter, such as a static relay, a switch controller including logic gates generating a trip signal based on predetermined criteria, and a manual switch for resetting the line interrupter. An embodiment comprises a voltage sensing coil enveloping a toroidal core to detect current variations in conductors passing through the core.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: April 17, 2007
    Assignee: Delphi Technologies, Inc.
    Inventors: Malakondaiah Naidu, Thomas J Schoepf, Suresh Gopalakrishnan
  • Publication number: 20060214670
    Abstract: An arc fault detector includes a shunt resistor deployed in a protected circuit, an arc discriminator sensing voltages across the shunt resistor and producing an arc indication deduced from current variations associated with parallel and series arc faults, a signal transformer buffering the arc detection signal and producing a pulse, a switch transient detector sensing a voltage differential across load switches and producing a pulsed switch transient signal when the voltage differential across load switches exceeds a reference value, a line interrupter, such as a static relay, a switch controller including logic gates generating a trip signal based on predetermined criteria, and a manual switch for resetting the line interrupter. An embodiment comprises a voltage sensing coil enveloping a toroidal core to detect current variations in conductors passing through the core.
    Type: Application
    Filed: December 20, 2005
    Publication date: September 28, 2006
    Inventors: Malakondaiah Naidu, Thomas Schoepf, Suresh Gopalakrishnan
  • Patent number: 7009406
    Abstract: The present invention discloses an arc fault detector including a shunt resistor deployed in a circuit being protected, an arc discriminator sensing voltages across the shunt resistor and outputting an arc detection signal when it detects current variations caused by parallel and series arc faults, a signal transformer buffering the arc detection signal and outputting a pulse, a switch transient detector detecting a voltage differential across load switches and outputting a pulsed switch transient detection signal when the voltage differential across load switches exceeds a reference value, a line interrupter such as a static relay, a switch controller including logic gates generating a trip signal based on predetermined criteria, and a manual switch for resetting the line interrupter. A second embodiment of the present invention senses voltage induced in a coil wrapped around a toroidal core to detect current variations in conductors which pass through the center of the toroidal core.
    Type: Grant
    Filed: April 23, 2004
    Date of Patent: March 7, 2006
    Assignee: Delphi Technologies, Inc.
    Inventors: Malakondaiah Naidu, Thomas J. Schoepf, Suresh Gopalakrishnan
  • Publication number: 20050103126
    Abstract: A torque sensing apparatus for picking up a magnetic field of a magnetostrictive material disposed on a shaft, comprising: a first integrating ring; a second integrating ring; a first fluxgate return strip and a second fluxgate return strip each being connected to the first integrating ring at one end and the second integrating ring at the other end; an excitation coil; and a feedback coil; wherein the first integrating ring and the second integrating ring are configured to be positioned to pick up flux signals along the entire periphery of the ends of the magnetostrictive material.
    Type: Application
    Filed: December 21, 2004
    Publication date: May 19, 2005
    Inventors: Malakondaiah Naidu, Joseph Heremans, Thomas Nehl, John Smith, Brian Fuller
  • Patent number: 6871553
    Abstract: A torque sensing apparatus for picking up a magnetic field of a magnetostrictive material disposed on a shaft, the torque sensing apparatus having: a first integrating ring; a second integrating ring; a first fluxgate return strip and a second fluxgate return strip each being connected to the first integrating ring at one end and the second integrating ring at the other end; an excitation coil; and a feedback coil; wherein the first integrating ring and the second integrating ring are configured to be positioned to pick up flux signals along the entire periphery of the ends of the magnetostrictive material.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: March 29, 2005
    Assignee: Delphi Technologies, Inc.
    Inventors: Malakondaiah Naidu, Joseph Pierre Heremans, Thomas Wolfgang Nehl, John R. Smith, Brian K Fuller
  • Publication number: 20040263183
    Abstract: The present invention discloses an arc fault detector including a shunt resistor deployed in a circuit being protected, an arc discriminator sensing voltages across the shunt resistor and outputting an arc detection signal when it detects current variations caused by parallel and series arc faults, a signal transformer buffering the arc detection signal and outputting a pulse, a switch transient detector detecting a voltage differential across load switches and outputting a pulsed switch transient detection signal when the voltage differential across load switches exceeds a reference value, a line interrupter such as a static relay, a switch controller including logic gates generating a trip signal based on predetermined criteria, and a manual switch for resetting the line interrupter. A second embodiment of the present invention senses voltage induced in a coil wrapped around a toroidal core to detect current variations in conductors which pass through the center of the toroidal core.
    Type: Application
    Filed: April 23, 2004
    Publication date: December 30, 2004
    Inventors: Malakondaiah Naidu, Thomas J. Schoepf, Suresh Gopalakrishnan
  • Patent number: 6833713
    Abstract: A direct current electrical circuit having a smart wire harness that has integrated electronics which measure both voltage and current through wires of the harness to detect and protect the electrical current from parallel and serial arc faults occurring within a protection zone. The protection zone is disposed directly between two smart connectors of the wire harness which are in communication with one another via a series of signal wires of the harness to detect serial or parallel arc faults within the protection zone. To measure serial arc faults, a voltage drop of the positive wire is measured at each smart connector and a difference taken which equals the serial arc voltage. If this voltage differential increases to a preset value, a switching device which provides power to the smart wire harness is opened.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: December 21, 2004
    Assignee: Delphi Technologies, Inc.
    Inventors: Thomas J. Schoepf, Malakondaiah Naidu, Suresh Gopalakrishan
  • Publication number: 20040187605
    Abstract: A torque sensing apparatus for picking up a magnetic field of a magnetostrictive material disposed on a shaft, comprising: a first integrating ring; a second integrating ring; a first fluxgate return strip and a second fluxgate return strip each being connected to the first integrating ring at one end and the second integrating ring at the other end; an excitation coil; and a feedback coil; wherein the first integrating ring and the second integrating ring are configured to be positioned to pick up flux signals along the entire periphery of the ends of the magnetostrictive material.
    Type: Application
    Filed: March 28, 2003
    Publication date: September 30, 2004
    Inventors: Malakondaiah Naidu, Joseph Pierre Heremans, Thomas Wolfgang Nehl, John R. Smith, Brian K. Fuller
  • Publication number: 20040187606
    Abstract: A torque sensing apparatus for picking up a magnetic flux in response to applying a torque to a shaft is disclosed. A magnetostrictive material is disposed on the surface of the shaft and is magnetically polarized. The apparatus includes a first flux collector and a second flux collector spaced from each other and extending annularly around the shaft. A first fluxgate is connected to the first flux collector at one end and to the second flux collector at the other end with a first excitation coil wound about the first fluxgate. A second fluxgate is connected to the first flux collector at one end and to the second flux collector at the other end with a second excitation coil wound about the second fluxgate. A feedback coil is positioned between the shaft and the flux collectors, the fluxgates, and the excitation coils.
    Type: Application
    Filed: January 23, 2004
    Publication date: September 30, 2004
    Inventors: Thomas Wolfgang Nehl, Joseph Pierre Heremans, Brian K. Fuller, John R. Smith, Malakondaiah Naidu, Avoki M. Omekanda
  • Publication number: 20040154887
    Abstract: A suspension control system includes a plurality of damper assemblies, each damper assembly including an integrated velocity sensor and an integrated local controller with a drive unit connected to a damper coil of the damper assembly. A central controller may be connected for communication with the integrated local controller of each damper assembly. The local controller of each damper assembly normally controls the damper assembly independently of the central controller or other damper assemblies for carrying out at least one control function of the damper assembly. When provided, the central controller communicates with the local controller of each damper assembly for overriding local control functions. A related self-contained piston damper unit is also provided.
    Type: Application
    Filed: November 26, 2003
    Publication date: August 12, 2004
    Inventors: Thomas W. Nehl, Fang Deng, David J. Barta, Eric L. Jensen, Bruce A. Heaston, Alexander A. Alexandridis, Malakondaiah Naidu, Suresh Gopalakrishnan
  • Publication number: 20040150410
    Abstract: A direct current electrical circuit having a smart wire harness that has integrated electronics which measure both voltage and current through wires of the harness to detect and protect the electrical current from parallel and serial arc faults occurring within a protection zone. The protection zone is disposed directly between two smart connectors of the wire harness which are in communication with one another via a series of signal wires of the harness to detect serial or parallel arc faults within the protection zone. To measure serial arc faults, a voltage drop of the positive wire is measured at each smart connector and a difference taken which equals the serial arc voltage. If this voltage differential increases to a preset value, a switching device which provides power to the smart wire harness is opened.
    Type: Application
    Filed: January 31, 2003
    Publication date: August 5, 2004
    Inventors: Thomas J. Schoepf, Malakondaiah Naidu, Suresh Gopalakrishan
  • Patent number: 6664768
    Abstract: An apparatus for controlling the load dump voltage of a permanent magnet (PM) alternator having a silicon controlled rectifier (SCR) bridge. The apparatus includes a voltage divider, a peak detector, and a comparator. The voltage divider attenuates the bridge output voltage, which is further fed through a peak detector to hold the peak value for improved stability. The comparator changes states when the bridge output exceeds a predetermined voltage level (e.g., 55 volts) that is less than the load dump threshold limit (e.g., 60 volts), but greater than the normal operating voltage (e.g., 42 volts). The comparator output change-in-state deactivates a gate pulse generator, thereby suppressing further operation of the SCR bridge. Voltage transients that may otherwise occur at the bridge output for the remainder portion of a half cycle from the PM alternator are clamped using a varistor or zener diode.
    Type: Grant
    Filed: May 21, 2001
    Date of Patent: December 16, 2003
    Assignee: Delphi Technologies, Inc.
    Inventors: Malakondaiah Naidu, Thomas Wolfgang Nehl
  • Patent number: 6605912
    Abstract: A three region control strategy for a permanent magnet motor is presented. In a first control region, the permanent magnet motor is operated at, a 120° conduction square wave mode at reduced phase current, and below a no-load speed. The motor phase current commutation causes eddy current losses in the rotor magnets and core which are insignificant due to the low phase currents and relatively low rotor speed. Meanwhile, the inverter switching losses are kept low as two switches are in use (on/off) for each current commutation during the 120° conduction mode. In a second control region, the permanent magnet motor is operated at a 180° conduction sinusoidal wave mode with high phase currents. The 180° conduction sinusoidal wave mode minimizes the commutation loss. In a third control region, the permanent magnet motor is operated above its no-load speed or in a field weakening mode.
    Type: Grant
    Filed: June 25, 1998
    Date of Patent: August 12, 2003
    Assignee: Delphi Technologies, Inc.
    Inventors: Aravind Sourirajan Bharadwaj, Fang Deng, Thomas Wolfgang Nehl, Malakondaiah Naidu
  • Patent number: 6566829
    Abstract: An exemplary embodiment of the invention is a method for torque control of a PM synchronous machine. The method includes obtaining a torque command signal and a machine speed and determining an operating mode in response to the torque command signal and the machine speed. The operating mode includes a first operating mode and a second operating mode. In the first operating mode, a stator phase voltage magnitude is computed and an angle between the stator phase voltage and a stator phase back emf is determined in response to the stator phase voltage magnitude. In the second operating mode, the stator phase voltage is set to a predetermined magnitude and the angle between the stator phase voltage and the stator phase back emf is determined in response to the predetermined magnitude.
    Type: Grant
    Filed: September 7, 2000
    Date of Patent: May 20, 2003
    Assignee: Delphi Technologies, Inc.
    Inventors: Malakondaiah Naidu, Rassem Ragheb Henry, Thomas Wolfgang Nehl
  • Patent number: 6486658
    Abstract: An encoder for a brushless motor of an Electric Power Steering (EPS) system that includes a commutation track coupled to a shaft for the generation of a commutation signal. The commutation signal in turn is used to generate an index signal every electrical cycle. The encoder further includes a set of high-resolution quadrature signal tracks. The set of high-resolution quadrature signal tracks generate a set of high-resolution signals which are phased at a set angular displacement with respect to one another. A set of sensors sense the commutation signal and the set of high resolution quadrature signals.
    Type: Grant
    Filed: February 16, 2001
    Date of Patent: November 26, 2002
    Assignee: Delphi Technologies, Inc.
    Inventor: Malakondaiah Naidu
  • Publication number: 20020171401
    Abstract: An apparatus for controlling the load dump voltage of a permanent magnet (PM) alternator having a silicon controlled rectifier (SCR) bridge. The apparatus includes a voltage divider, a peak detector, and a comparator. The voltage divider attenuates the bridge output voltage, which is further fed through a peak detector to hold the peak value for improved stability. The comparator changes states when the bridge output exceeds a predetermined voltage level (e.g., 55 volts) that is less than the load dump threshold limit (e.g., 60 volts), but greater than the normal operating voltage (e.g., 42 volts). The comparator output change-in-state deactivates a gate pulse generator, thereby suppressing further operation of the SCR bridge. Voltage transients that may otherwise occur at the bridge output for the remainder portion of a half cycle from the PM alternator are clamped using a varistor or zener diode.
    Type: Application
    Filed: May 21, 2001
    Publication date: November 21, 2002
    Inventors: Malakondaiah Naidu, Thomas Wolfgang Nehl
  • Patent number: 6465975
    Abstract: A novel method is proposed for controlling the torque of a PM brushless motor with sinusoidal back-emfs without current sensors by computing the required input phase voltages with measured rotor position and speed and known machine parameters. These voltages are fed to the machine at an angle computed in terms of input parameters and the phase voltage with respect to their back-emfs so that phase currents are aligned with their back-emfs to exactly mimic the performance of the current mode controller.
    Type: Grant
    Filed: September 18, 2000
    Date of Patent: October 15, 2002
    Assignee: Delphi Technologies, Inc.
    Inventor: Malakondaiah Naidu
  • Patent number: 6404150
    Abstract: An electric vehicle accessory motor drive power supply system (40) that utilizes a single power supply design to provide efficient variable speed motor control to both brushless and brush-type DC motors (42,44). The power supply system includes at least one of each type of motor along with a first DC-DC converter (46) that provides operating power to the brushless motor (42) and a second DC-DC converter (48) that provides operating power to the brush-type motor (44). Both converters (46,48) have a power input (52) connected to the electric vehicle's high voltage bus (50) and each includes a data input (54) for receiving a speed control signal (SC) indicative of desired motor speed, as well as an output (56) for providing a motor drive signal to its associated DC motor (42,44).
    Type: Grant
    Filed: June 27, 2000
    Date of Patent: June 11, 2002
    Assignee: General Motors Corporation
    Inventors: Thomas Wolfgang Nehl, Malakondaiah Naidu, Avoki Omekanda, Anita B. Rao, Lateef A. Kajouke, Mark M. Osugi