US4973902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fault detector for aircraft variable speed, constant frequency power supply
Assignee: Sundstrand Corp
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Filing: 1989-12-11
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Granted: 1990-11-27
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Expires: 2009-12-11
Abstract
Abstract A variable speed, constant frequency aircraft power system uses current sensing diodes to rectify the power generator output. The current flow through pairs of diodes is compared to generate phase currents to detect feeder faults.
Inventors
- 👤 John Dhyanchand
- 👤 Vietson Nguyen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:51
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
112 words
A fault detector for a variable speed, constant frequency aircraft power system, comprising in combination; a three phase power generator; means for generating a signal which is a function of the current flow in one phase of said generator; a three phase rectifier; power leads coupling said generator to said rectifier; said rectifier including at least one pair of diodes, each with an integral current sensor; means for combining an output of said current sensor of each of said pair of diodes to generate a signal which is a function of said phase current at said rectifier, and means for comparing said generator phase current signal and said rectifier phase current signal.
Claim 2
Dependent Claim
112 words
A fault detector for a variable speed, constant frequency aircraft power system, comprising in combination; a three phase power generator; means for generating a signal which is a function of the current flow in one phase of said generator; a three phase rectifier; power leads coupling said generator to said rectifier; said rectifier including at least one pair of diodes, each with an integral current sensor; means for combining an output of said current sensor of each of said pair of diodes to generate a signal which is a function of said phase current at said rectifier, and means for comparing said generator phase current signal and said rectifier phase current signal.
Claim 3
Dependent Claim
41 words
A fault detector for a variable speed, constant frequency aircraft power system as in claim 1 wherein said means for generating a signal which is a function of the current flow in one phase of said generator is a current transformer.
Claim 4
Dependent Claim
26 words
A fault detector for a variable speed, constant frequency aircraft power system as in claim 1 wherein said combining means includes a pair of operational amplifiers.
Claim 5
Dependent Claim
31 words
A fault detector for a variable speed, constant frequency aircraft power system as in claim 1 wherein said generator phase current signal and said rectifier phase current signals are voltage signals.
Claim 6
Dependent Claim
31 words
A fault detector for a variable speed, constant frequency aircraft power system as in claim 2 wherein said generator phase current signal and said rectifier phase current signals are voltage signals.
Claim 7
Dependent Claim
31 words
A fault detector for a variable speed, constant frequency aircraft power system as in claim 3 wherein said generator phase current signal and said rectifier phase current signals are voltage signals.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-26 | 1994-05-28 | 1994-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-26 | 1998-05-28 | 1998-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-26 | 2002-05-28 | 2002-11-27 | $7700.00 | Window Closed / Lapsed |