Patents by Inventor Narasimha K. Reddy

Narasimha K. Reddy 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).

  • Enhanced polyphase motor operation using a solid state inverter
    Patent number: 5294875
    Abstract: A polyphase motor is powered by an inverter. Each phase winding in the motor comprises two electrically insulated, electromagnetically coupled, conductors, making up a "phase bundle." Each conductor in the bundle is powered by its own transistor drive. The drives for each phase winding respond to a common phase signal for instance from a pulse width modulator.
    Type: Grant
    Filed: February 15, 1991
    Date of Patent: March 15, 1994
    Assignee: Otis Elevator Company
    Inventor: Narasimha K. Reddy
  • Brake sequenced elevator motor speed control
    Patent number: 4975627
    Abstract: In an elevator, an electric motor is connected to a brake through a gearbox. The brake is controlled with an electromagnet. A torque signal is applied to the motor. Brake voltage characteristics are used to detect actual brake engagement and to signal a switch to substitute a decaying torque control signal to the motor for the motor torque signal supplied to the motor while the elevator is moving. Motor torque is thereby gradually rather than suddenly reduced to zero.
    Type: Grant
    Filed: August 15, 1988
    Date of Patent: December 4, 1990
    Assignee: Otis Elevator Company
    Inventor: Narasimha K. Reddy