Patents by Inventor P. R. K. Chetty

P. R. K. Chetty 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: 4625271
    Abstract: A soft-start circuit for an inverter having a switch which is operated in accordance with the output of an oscillator includes a ramp generator coupled to the oscillator for generating a cycle ramp signal synchronized to and having the same period as the oscillator output, the cycle ramp signal also having an amplitude which periodically increases between first and second levels. Means are included for generating a soft-start signal having an amplitude which increases between the first and second levels, the length of time required for the amplitude of the soft-start signal to increase from the first level to the second level being substantially longer than the period of the cycle ramp signal. Means are coupled to the ramp generator and to the soft-start signal generating means for comparing the two signals to develop a pulse width modulated enable signal having a series of pulses of gradually increasing pulse width.
    Type: Grant
    Filed: October 5, 1984
    Date of Patent: November 25, 1986
    Assignee: Sundstrand Corporation
    Inventors: P. R. K. Chetty, Gary Galloway, Pierre Thollot
  • Patent number: 4604567
    Abstract: A system for transferring maximum power from a solar cell array by loading the array in a manner which forces it to operate at its maximum power point. The system samples the open circuit voltage of the solar cell array to provide a signal proportional to the voltage of the array at its maximum power point. The sampled open circuit voltage is compared to the operating voltage of the solar cell array to provide an error signal which is proportional to the difference between the maximum power point voltage and the operating voltage of the array. The amount of power transferred from the array to a load is altered in accordance with the error signal to operate the array at its maximum power point.
    Type: Grant
    Filed: October 11, 1983
    Date of Patent: August 5, 1986
    Assignee: Sundstrand Corporation
    Inventor: P. R. K. Chetty
  • Patent number: 4542440
    Abstract: A push-pull converter has transistor power switches which conduct alternately to connect a DC source with the primary windings of an output transformer. A turn-off snubber circuit is connected with each power switch. When a power switch is turned on, snubber current pulses flow in the circuits connected with both switches. A switch current sensor circuit has a current transformer with an output winding inductively coupled with each of the conductors connected between the power switches and the primary windings of the output transformer. The snubber current pulses through the conductors are out of phase and are suppressed in the current transformer output. The switch current signal from the secondary of the current transformer is free of snubber current pulses and is used in a flux balance circuit and in a pulse-by-pulse current limiter.
    Type: Grant
    Filed: November 2, 1983
    Date of Patent: September 17, 1985
    Assignee: Sundstrand Corporation
    Inventors: P. R. K. Chetty, John Dhyanchand, Pierre Thollot
  • Patent number: 4480297
    Abstract: A direct current to alternating current inverter with an output transformer is regulated by a pulse width modulator which alternately closes one of two switches connected with the center tapped primary winding of the output transformer. A synchronizing circuit for the pulse width modulator has means for gating synchronizing pulses to the clock of the modulator, blocking synchronizing signals which would cause an unbalance in the duty cycles of the switches and saturation of the output transformer.
    Type: Grant
    Filed: March 31, 1983
    Date of Patent: October 30, 1984
    Assignee: Sundstrand Corporation
    Inventors: P. R. K. Chetty, Donald G. Fair