Patents by Inventor Sunil Patel

Sunil Patel 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: 5282125
    Abstract: Control pulses having a first frequency are supplied to the switches of an inverter by a controller. During initial operation of the inverter, however, a softstart circuit supplied pulses to the inverter switches of the inverter wherein the soft-start pulses have a second frequency. The second frequency is constant and higher than the first frequency.
    Type: Grant
    Filed: May 13, 1992
    Date of Patent: January 25, 1994
    Assignee: Sundstrand Corporation
    Inventors: P. John Dhyanchand, Chai-Nam Ng, Sunil Patel, Vietson M. Nguyen
  • Patent number: 5225973
    Abstract: A regulator circuit for an inverter having first and second inverter sections that develop first and second AC waveforms which are phase displaced by a variable angle .alpha. wherein the first and second AC waveforms are combined to produce AC output power includes a reference signal generator that develops a reference signal having a transition between two states at a first time, a memory storing a plurality of words each representing a value of .alpha. add a circuit for accessing the memory with a deviation signal such that the memory provides a word at an output thereof. A counter is provided and a timing circuit causes the counter to load the word at a time prior to the first time. At the first time a gating circuit provides a plurality of clock pulses to a clock input of the counter whereby the counter decrements the loaded word as the clock pulses are received by the counter.
    Type: Grant
    Filed: September 13, 1990
    Date of Patent: July 6, 1993
    Inventors: Sunil Patel, Chai-Nam Ng, Vietson Nguyen, P. John Dhyanchand
  • Patent number: 5041958
    Abstract: An inverter for use in a power conversion system of the type used in an aircraft, for example, includes a first subinverter pair that generates a first pair of waveforms and a second subinverter pair that generates a second pair of waveforms. The two subinverter pairs are connected to a summing transformer having two pairs of primary windings and a plurality of secondary windings coupled to the primary windings. A regulator is coupled to the output of the summing transformer and varies the phase angles between the waveforms generated by the two subinverter pairs based upon the voltage and current at the output of the summing transformer in order to regulate the voltage at the output of the summing transformer.
    Type: Grant
    Filed: December 20, 1989
    Date of Patent: August 20, 1991
    Assignee: Sundstrand Corporation
    Inventors: P. John Dhyanchand, Sunil Patel, Chai-nam Ng, Vietson Nguyen
  • Patent number: 5041957
    Abstract: An inverter for use in a power conversion system of the type used in an aircraft, for example, includes a first subinverter pair that generates a first pair of waveforms, a second subinverter pair that generates a second pair of waveforms, and a third subinverter pair that generates a third pair of waveforms. The three subinverter pairs are connected to a summing transformer having first, second and third transformers. A regulator is coupled to the output of the summing transformer and varies the phase angles between the three pairs of waveforms generated by the three subinverter pairs based upon the voltage and current at the output of the summing transformer in order to regulate the voltage at the output of the summing transformer.
    Type: Grant
    Filed: December 20, 1989
    Date of Patent: August 20, 1991
    Assignee: Sundstrand Corporation
    Inventors: P. John Dhyanchand, Sunil Patel, Chai-Nan Ng, Vietson Nguyen
  • Patent number: 5040105
    Abstract: An inverter for use in a variable-speed, constant-frequency power conversion system of the type used in an aircraft, for example, includes a four subinverter pairs, each of which generates a respective set of waveforms. The four subinverter pairs are connected to a summing transformer having eight sets pairs of primary windings and eight sets of secondary windings coupled to the primary windings. A regulator is coupled to the output of the summing transformer and varies the phase angles between the waveforms generated by the four subinverter pairs based upon the voltage and current at the output of the summing transformer in order to regulate the voltage at the output of the summing transformer.
    Type: Grant
    Filed: December 20, 1989
    Date of Patent: August 13, 1991
    Assignee: Sundstrand Corporation
    Inventors: P. John Dhyanchand, Sunil Patel, Chai-Nam Ng, Vietson Nguyen
  • Patent number: 5031086
    Abstract: A hybrid power system which converts variable-frequency power developed by a brushless generator into DC power which is supplied to a DC load and constant-frequency AC power which is supplied to an AC load includes an AC/DC converter coupled to a main generator portion armature winding of the generator which converts the variable-frequency power produced by the generator into the DC power and a DC/AC converter coupled to the AC/DC converter which converts the DC power into the constant-frequency AC power. A first regulator is coupled to an exciter portion field winding of the generator for supplying current thereto in dependence upon a parameter of the DC power to maintain such parameter substantially at a regulated DC value. A second regulator is coupled to the DC/AC converter for controlling same in accordance with a parameter of the constant-frequency AC power to maintain such parameter substantially at a regulated AC value.
    Type: Grant
    Filed: December 20, 1989
    Date of Patent: July 9, 1991
    Assignee: Sundstrand Corporation
    Inventors: P. John Dhyanchand, Sunil Patel, Chai-Nam Ng, Vietson Nguyen
  • Patent number: 5027265
    Abstract: A regulator for a stepped-waveform inverter having first and second subinverters which produce waveforms having a variable phase displacement therebetween and a summing transformer which sums the outputs of the subinverters includes circuitry for detecting a deviation of a parameter of the AC output power produced by the inverter from a reference and circuitry coupled to the detecting circuitry for deriving a phase command signal from the detected deviation. A comparator compares the phase command signal with a ramp signal to obtain a comparison signal and circuitry operates the first and second subinverters responsive to the comparison signal to cause the phase displacement to vary in accordance with the phase command signal.
    Type: Grant
    Filed: December 20, 1989
    Date of Patent: June 25, 1991
    Assignee: Sundstrand Corporation
    Inventors: P. John Dhyanchand, Sunil Patel, Chai-Nam Ng, Vietson Nguyen
  • Patent number: 5012177
    Abstract: Prior power conversion system operable in generating and starting modes have utililzed brushless generators which are suitable for only certain applications. In order to overcome this problem, a power conversion system operable in generating and starting modes utilizes a switched reluctance motor/generator which is reliable and inexpensive and which can be used in a variety of environments.
    Type: Grant
    Filed: December 19, 1989
    Date of Patent: April 30, 1991
    Assignee: Sundstrand Corporation
    Inventors: P. John Dhyanchand, Sunil Patel, Chai-Nam Ng, Vietson Nguyen
  • Patent number: 5008797
    Abstract: Prior power converters utilizing a plurality of switches operated by control circuitry include many components which are subject to failure. When such a failure occurs, it may prove difficult to isolate the problem and repair the power converter. In order to overcome this problem, a power converter is packaged as a plurality of identical line replaceable units each of which may be easily replaced in the event of a malfunction.
    Type: Grant
    Filed: December 20, 1989
    Date of Patent: April 16, 1991
    Assignee: Sundstrand Corporation
    Inventors: Sunil Patel, Robert Ligon, P. John Dhyanchand