Patent US3869645A successfully refreshed from Google Patents.
US3869645A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spark ignition systems
Assignee: Northrop Grumman Properties Ltd
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Filing: 1973-03-26
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Granted: 1975-03-04
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Expires: 1993-03-26
Abstract
Abstract A spark ignition system for a gas turbine engine includes a capacitor, a spark gap connected in series with a pair of output terminals and the capacitor, the output terminals in use being connected to a spark discharge device associated with the engine. The spark gap acts when the voltage across the capacitor attains a predetermined value to provide a conductive path between the capacitor and the output terminals and a power supply is provided for charging the capacitor. The power supply includes means for adjusting the rate of charge of the capacitor so that the spark discharge rate can be adjusted.
Inventors
- 👤 Keith Douglas Collins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:56
CPC Classifications
F; F02; F02P; F02P15/00; F02P15/001; F02P15/003; F02C; F02C7/00; F02C7/26; F02C7/264; F02C7/266
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
149 words
A spark ignition system for continuous combustion gas turbine engines comprising a capacitor, a spark gap connected in series with the capacitor and a pair of output terminals, said output terminals in use, being connected to a spark discharge device associated with the engine, the spark gap acting when the voltage across the capacitor attains a predetermined value, to provide a conductive path so that the capacitor is discharged through said device, means for charging the capacitor, said means comprising a power supply including a transformer having primary and secondary windings, rectifier means connected in series with said secondary winding and the capacitor, means for applying a pulsed electric supply to the primary winding of the transformer, and further means for adjusting the peak current flowing in the primary winding of the transformer whereby the rate of change of the capacitor and the spark discharge rate can be adjusted.
Claim 2
Dependent Claim
149 words
A spark ignition system for continuous combustion gas turbine engines comprising a capacitor, a spark gap connected in series with the capacitor and a pair of output terminals, said output terminals in use, being connected to a spark discharge device associated with the engine, the spark gap acting when the voltage across the capacitor attains a predetermined value, to provide a conductive path so that the capacitor is discharged through said device, means for charging the capacitor, said means comprising a power supply including a transformer having primary and secondary windings, rectifier means connected in series with said secondary winding and the capacitor, means for applying a pulsed electric supply to the primary winding of the transformer, and further means for adjusting the peak current flowing in the primary winding of the transformer whereby the rate of change of the capacitor and the spark discharge rate can be adjusted.
Claim 3
Dependent Claim
27 words
A spark ignition system according to claim 1 in which said further means includes a variable impedance connected in series with the primary winding of the transformer.
Claim 4
Dependent Claim
81 words
A spark ignition system according to claim 1 in which said means comprises a transistor for controlling flow of current in the primary winding of the transformer, the transformer having a feedback winding for effecting switching of the transistor, first circuit means for supplying current to the base of the transistor and in which said further means comprises second circuit means for supplying a different value of current to the base of the transistor when a different spark rate is required.
Claim 5
Dependent Claim
39 words
A spark ignition system according to claim 3 in which each of said circuit means includes a Zener diode, said Zener diodes acting to determine the peak value of the current flowing in the primary winding of the transformer.
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) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |