DR. SUNIL SHASHIKANT PATEL, M.D.
Osteopathic Medicine at Roxbury Rd, Rockford, IL

5225973, Jul 6, 1993

Sep 13, 1990

7/581924

Sunil Patel - Rockford IL
Vietson Nguyen - Rockford IL
P. John Dhyanchand - Rockford IL

H02M 112

363 43

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. A zero detect circuit and a one-shot coupled to the output of the counter produce a synchronization signal having a transition between two states at a second time subsequent to the first time when the loaded word is decremented to a particular value.

5301098, Apr 5, 1994

Jul 9, 1992

7/911549

P. John Dhyanchand - Rockford IL
Vietson M. Nguyen - Rockford IL
Sunil Patel - Rockford IL

Sundstrand Corporation - Rockford IL

H02M 7537

363 97

An inverter system for inverting variable input DC and providing therefrom controlled output AC including a feedforward sensor for sensing a variable parameter of the input DC, a feedback AC sensor for sensing the controlled output AC and an inverter controller responsive to the variable parameter of the input DC and to the controlled output AC for regulating the magnitude of the controlled output AC.

5041957, Aug 20, 1991

Dec 20, 1989

7/453972

P. John Dhyanchand - Rockford IL
Sunil Patel - Rockford IL
Vietson Nguyen - Rockford IL

Sundstrand Corporation - Rockford IL

H02M 112, H02M 5458

363 43

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.

5027265, Jun 25, 1991

Dec 20, 1989

7/453975

P. John Dhyanchand - Rockford IL
Sunil Patel - Rockford IL
Vietson Nguyen - Rockford IL

Sundstrand Corporation - Rockford IL

H02M 3335

363 37

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.

5008797, Apr 16, 1991

Dec 20, 1989

7/453974

Sunil Patel - Rockford IL
Robert Ligon - Rockford IL
P. John Dhyanchand - Rockford IL

Sundstrand Corporation - Rockford IL

H02M 114

363 43

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.

5041958, Aug 20, 1991

Dec 20, 1989

7/454433

P. John Dhyanchand - Rockford IL
Sunil Patel - Rockford IL
Vietson Nguyen - Rockford IL

Sundstrand Corporation - Rockford IL

H02M 112, H02M 5458

363 43

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.

5282125, Jan 25, 1994

May 13, 1992

7/882391

P. John Dhyanchand - Rockford IL
Sunil Patel - Rockford IL
Vietson M. Nguyen - Rockford IL

Sundstrand Corporation - Rockford IL

H02M 75387

363 49

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.

5040105, Aug 13, 1991

Dec 20, 1989

7/454434

P. John Dhyanchand - Rockford IL
Sunil Patel - Rockford IL
Vietson Nguyen - Rockford IL

Sundstrand Corporation - Rockford IL

H02M 3335

363 43

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.

5031086, Jul 9, 1991

Dec 20, 1989

7/454009

P. John Dhyanchand - Rockford IL
Sunil Patel - Rockford IL
Vietson Nguyen - Rockford IL

Sundstrand Corporation - Rockford IL

H02M 3335

363 37

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.