US3956884A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas turbine engine fuel control systems
Assignee: ZF International UK Ltd
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Filing: 1975-07-07
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Granted: 1976-05-18
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Expires: 1995-07-07
Abstract
Abstract An electronic fuel control for a gas turbine engine comprises a manual control for setting the desired value of an engine parameter, an error amplifier connected to produce an error signal corresponding to the difference between the output of the control and an integrator, the output of the integrator controlling the supply of fuel to the engine. The error amplifier is connected to the integrator through a variable limiter, which applies a limit to the error in accordance with the difference between the integrator output and the actual value of the parameter. The limiter causes the error signal to go negative if this difference becomes too great.
Inventors
- 👤 Richard John Eves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:12
CPC Classifications
F; F02; F02C; F02C9/00; F02C9/26; F02C9/32
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
203 words
A gas turbine engine fuel control system of the kind comprising a speed governor and means for supplying to the speed governor a speed datum signal, such means including an acceleration control means whereby a limit is placed on the rate of increase of the datum speed signal in accordance with prevailing engine conditions, in which the means for supplying the speed governor with a speed datum signal comprises an integrator, a first difference amplifier comparing the output of the integrator with a demand signal corresponding to the required value of an engine parameter, a limiter circuit connecting the output terminal of the first difference amplifier to the input terminal of the integrator and a second difference amplifier for comparing the output of the integrator with a signal corresponding to the actual value of said engine parameter, said limiter circuit being controlled by the output of the second difference amplifier to decrease the limit applied to the output of the first difference amplifier as the output of the second difference amplifier increases and to reduce the input to the integrator to a negative value (to decrease the output of the integrator) when the output of the second difference amplifier exceeds a predetermined value.
Claim 2
Dependent Claim
203 words
A gas turbine engine fuel control system of the kind comprising a speed governor and means for supplying to the speed governor a speed datum signal, such means including an acceleration control means whereby a limit is placed on the rate of increase of the datum speed signal in accordance with prevailing engine conditions, in which the means for supplying the speed governor with a speed datum signal comprises an integrator, a first difference amplifier comparing the output of the integrator with a demand signal corresponding to the required value of an engine parameter, a limiter circuit connecting the output terminal of the first difference amplifier to the input terminal of the integrator and a second difference amplifier for comparing the output of the integrator with a signal corresponding to the actual value of said engine parameter, said limiter circuit being controlled by the output of the second difference amplifier to decrease the limit applied to the output of the first difference amplifier as the output of the second difference amplifier increases and to reduce the input to the integrator to a negative value (to decrease the output of the integrator) when the output of the second difference amplifier exceeds a predetermined value.
Claim 3
Dependent Claim
76 words
A system as claimed in claim 1 in which the limiter circuit includes a function generator controlled by the output of the second difference amplifier and providing an output signal which has a maximum value when the output of the second difference amplifier is zero, which decreases relatively slowly with increasing values of the output of the second differene amplifier for low values of that output, but decreases more sharply for higher values of that output.
References Cited (Backward Citations)
US2941359A
Cited
US3295316A
Cited
US3381470A
Cited
US3533236A
Cited
US3488948A
Cited
US3606754A
Cited
GB1386401A
Cited
US3844114A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-18 | 1979-11-17 | 1980-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-18 | 1983-11-17 | 1984-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-18 | 1987-11-17 | 1988-05-18 | $7700.00 | Window Closed / Lapsed |