Patents by Inventor Ramamoorthy Rajagopalan

Ramamoorthy Rajagopalan 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: 6914349
    Abstract: Systems and methods of universal uninterruptible power supply (UPS) input circuitry are provided. The input circuitry of the present invention enables a UPS system to simply connect and operate in conjunction with any suitable backup power system. In particular, once a user indicates what backup system is attached to the input circuitry, a software unit automatically configures the input circuitry to operate with the coupled backup system. Once configured, the software unit may control portions of the input circuitry such that power is continuously provided to a load. For example, once a user indicates that a flywheel based backup system is attached, the software unit may instruct the input circuitry to maintain a predetermined flywheel speed (e.g., RPM) to ensure that the system is in constant ready state to deliver backup power.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: July 5, 2005
    Assignee: Active Power, Inc.
    Inventor: Ramamoorthy Rajagopalan
  • Publication number: 20030160514
    Abstract: Systems and methods of universal uninterruptible power supply (UPS) input circuitry are provided. The input circuitry of the present invention enables a UPS system to simply connect and operate in conjunction with any suitable backup power system. In particular, once a user indicates what backup system is attached to the input circuitry, a software unit automatically configures the input circuitry to operate with the coupled backup system. Once configured, the software unit may control portions of the input circuitry such that power is continuously provided to a load. For example, once a user indicates that a flywheel based backup system is attached, the software unit may instruct the input circuitry to maintain a predetermined flywheel speed (e.g., RPM) to ensure that the system is in constant ready state to deliver backup power.
    Type: Application
    Filed: February 27, 2002
    Publication date: August 28, 2003
    Inventor: Ramamoorthy Rajagopalan
  • Patent number: 5982645
    Abstract: A power conversion system is described which includes a power input for accepting a waveform at a given power level and frequency, and a power output for providing an output waveform at a second given power level. A DC to AC converter accepts a waveform based on an input wave form from the power input and converts the waveform to an AC waveform having a frequency at least approximately an order of magnatude higher than the frequency of the input waveform for application to a DC to AC converter output. An AC converter accepts the output waveform from the DC to AC converter output and provides a converted waveform from an output of the AC converter to the power output. A coupling device operates at the frequency of the converter output for coupling the output of the DC to AC converter to the AC converter.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: November 9, 1999
    Assignee: Square D Company
    Inventors: Alexander Levran, Joseph Marion Nowosielski, Giao Mong Ton-That, Ramamoorthy Rajagopalan, Henri Mabboux, David Mazur
  • Patent number: 5592137
    Abstract: The present invention locates the primary winding of a transformer in a configuration where it substantially surrounds the secondary winding of the transformer in order to enhance the efficiency of the electromagnetic coupling. High magnetic permeability material surrounds portions of the primary winding of the transformer. The transformer is designed to efficiently operate at frequencies of approximately 50 kilohertz. In one preferred embodiment, the primary winding of the invention is formed of two U-shapes in which the parallel members of the U are substantially longer than the bottom portion of the U. The two U-shapes form a rectangular shape and the substantially parallel rectangular portions are surrounded by high magnetic permeability material to further enhance the electromagnetic coupling between the primary coil winding and the secondary coil winding. In another embodiment, the primary winding of the invention may be rectangular in shape.
    Type: Grant
    Filed: September 25, 1992
    Date of Patent: January 7, 1997
    Assignee: Square D Company
    Inventors: Alexander Levran, Joseph M. Nowosielski, Giao M. Ton-That, Ramamoorthy Rajagopalan
  • Patent number: 5521811
    Abstract: The present invention locates the primary winding of a transformer in a configuration where it substantially surrounds the secondary winding of the transformer in order to enhance the efficiency of the electromagnetic coupling. High magnetic permeability material surrounds portions of the primary winding of the transformer. The transformer is designed to efficiently operate at frequencies of approximately 50 kilohertz. In one preferred embodiment, the primary winding of the invention is formed of two U-shapes in which the parallel members of the U are substantially longer than the bottom portion of the U. The two U-shapes form a rectangular shape and the substantially parallel rectangular portions are surrounded by high magnetic permeability material to further enhance the electromagnetic coupling between the primary coil winding and the secondary coil winding. In another embodiment, the primary winding of the invention may be rectangular in shape.
    Type: Grant
    Filed: September 12, 1994
    Date of Patent: May 28, 1996
    Assignee: Square D Company
    Inventors: Alexander Levran, Joseph M. Nowosielski, Giao M. Ton-That, Ramamoorthy Rajagopalan
  • Patent number: 5491624
    Abstract: The present invention converts an alternating current input into a direct current output by switching a current load at high speeds to create a voltage envelope having a maximum allowed voltage and a minimum allowed voltage. Complementary switching elements are employed to take advantage of both the positive and negative portions of an AC cycle. Load switching is arranged so that the current vector which represents the load is nearly coincident with the voltage vector which represents the power source. The system can operate in an open loop mode at a constant frequency, in a closed loop mode, or in a hysteresis mode. During open loop operation, the voltage envelope is not rigidly defined as the switching frequency remains constant. During hysteresis mode control, the voltage envelope remains fixed and the current switching frequency varies.
    Type: Grant
    Filed: October 24, 1994
    Date of Patent: February 13, 1996
    Assignee: Square D Company
    Inventors: Alexander Levran, Joseph M. Nowosielski, Giao M. Ton-That, Ramamoorthy Rajagopalan, Henri Mabboux
  • Patent number: 5414609
    Abstract: A pulse width modulation DC to DC converter operates in an open loop mode to convert the DC output of the AC to DC converter to a desired, predetermined DC level using pulse width modulation techniques and a switching configuration substantially similar to that of the AC to DC converter.
    Type: Grant
    Filed: August 25, 1992
    Date of Patent: May 9, 1995
    Assignee: Square D Company
    Inventors: Alexander Levran, Joseph M. Nowosielski, Giao M. Ton-That, Ramamoorthy Rajagopalan