Patents by Inventor Narayana Prakash Saligram

Narayana Prakash Saligram 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: 8581554
    Abstract: Disclosed are methods for charging batteries utilizing a charge balance approach, and charger systems using those methods. In one example, a method for charging a battery includes monitoring an amount of charge released by the battery while in a discharge state, recording the amount of charge released while in the discharge state, applying a voltage which results in current in reverse direction to the battery at a first voltage level for a time sufficient to introduce an amount of charge substantially equal to the recorded amount of charge released by the battery while in the discharge state, and maintaining the battery in a stand-by mode by applying a voltage which results in current in reverse direction to the battery at a second voltage level, the second voltage level being in a range sufficient to prevent self-discharge of the battery and insufficient to induce evaporation of electrolyte in the battery.
    Type: Grant
    Filed: July 10, 2009
    Date of Patent: November 12, 2013
    Assignee: Schneider Electric IT Corporation
    Inventors: Narayana Prakash Saligram, Sreejakumar Sreekantan Nair, Ramakrishnan Madenoor Krishnan, Milind Dighrasker
  • Patent number: 8148853
    Abstract: A switch circuit and method for converting a hard switch into a soft switch. In one example, the circuit includes a first switch having a first node and a second node, and a switch control circuit coupled in parallel with the first switch between the first and second nodes. The switch control circuit includes a series resonant circuit including a capacitor and an inductor coupled together in series, a second switch coupled in parallel with the series resonant circuit, a third switch coupled in series between the first node and the series resonant circuit, and a first diode coupled between the series resonant circuit and the second node, an negative terminal of the first diode being coupled to the second node.
    Type: Grant
    Filed: December 30, 2009
    Date of Patent: April 3, 2012
    Assignee: American Power Conversion Corporation
    Inventors: Narayana Prakash Saligram, Sreejakumar Sreekantan Nair, Pradeep Thalli
  • Publication number: 20110156495
    Abstract: A switch circuit and method for converting a hard switch into a soft switch. In one example, the circuit includes a first switch having a first node and a second node, and a switch control circuit coupled in parallel with the first switch between the first and second nodes. The switch control circuit includes a series resonant circuit including a capacitor and an inductor coupled together in series, a second switch coupled in parallel with the series resonant circuit, a third switch coupled in series between the first node and the series resonant circuit, and a first diode coupled between the series resonant circuit and the second node, an negative terminal of the first diode being coupled to the second node.
    Type: Application
    Filed: December 30, 2009
    Publication date: June 30, 2011
    Inventors: Narayana Prakash Saligram, Sreejakumar Sreekantan Nair, Pradeep Thalli
  • Publication number: 20110006737
    Abstract: Disclosed are methods for charging batteries utilizing a charge balance approach, and charger systems using those methods. In one example, a method for charging a battery includes monitoring an amount of charge released by the battery while in a discharge state, recording the amount of charge released while in the discharge state, applying a voltage which results in current in reverse direction to the battery at a first voltage level for a time sufficient to introduce an amount of charge substantially equal to the recorded amount of charge released by the battery while in the discharge state, and maintaining the battery in a stand-by mode by applying a voltage which results in current in reverse direction to the battery at a second voltage level, the second voltage level being in a range sufficient to prevent self-discharge of the battery and insufficient to induce evaporation of electrolyte in the battery.
    Type: Application
    Filed: July 10, 2009
    Publication date: January 13, 2011
    Inventors: Narayana Prakash Saligram, Sreejakumar Sreekantan Nair, Ramakrishnan Madenoor Krishnan, Milind Dighrasker