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US3928962A Expired / Lapsed US ⏱️ 0.0 years remaining

Fuel control systems for gas turbine engines

Assignee: Northrop Grumman Properties Ltd
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Filing: 1974-04-26
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Granted: 1975-12-30
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Expires: 1994-04-26
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Abstract

Abstract A fuel control system for a gas turbine engine includes means for producing an electrical signal corresponding to engine speed, means for producing an electrical signal corresponding to the desired engine speed, a first difference amplifier for producing an error signal corresponding to the difference between the desired and actual engine speeds, a limit circuit which imposes a variable limit on the magnitude of the error signal, an integrater connected to produce an output signal corresponding to the time integral of the output of the limit circuit, a second difference amplifier connected to compare the integrator output with the actual speed signal, an electrically actuated fuel flow control controlling fuel flow to the engine in accordance with the output of the second difference amplifier, said limit circuit being responsive only to the output of the second difference amplifier.

Inventors

  • 👤 Paul Mainwaring Maker

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 16:48
CPC Classifications
F; F02; F02C; F02C9/00; F02C9/26; F02C9/32

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 154 words
A fuel control system for a gas turbine engine comprising means for producing an electrical signal corresponding to the actual engine speed, means for producing an electrical signal corresponding to the desired engine speed, a first difference amplifier connected to both of said means, and arranged to produce an error signal corresponding to the difference between the desired and actual speeds, a limit circuit which imposes a variable limit on the magnitude of said error signal, an integrator connected to produce an output corresponding to the time integral of the output of the limit circuit, a second difference amplifier connected to compare the output of the integrator with the signal corresponding to the actual speed and an electrically actuated fuel flow control for controlling the fuel flow to the engine, in accordance with the output of the second difference amplifier, said limit circuit being responsive only to the output of the second difference amplifier.
Claim 2
Dependent Claim 154 words
A fuel control system for a gas turbine engine comprising means for producing an electrical signal corresponding to the actual engine speed, means for producing an electrical signal corresponding to the desired engine speed, a first difference amplifier connected to both of said means, and arranged to produce an error signal corresponding to the difference between the desired and actual speeds, a limit circuit which imposes a variable limit on the magnitude of said error signal, an integrator connected to produce an output corresponding to the time integral of the output of the limit circuit, a second difference amplifier connected to compare the output of the integrator with the signal corresponding to the actual speed and an electrically actuated fuel flow control for controlling the fuel flow to the engine, in accordance with the output of the second difference amplifier, said limit circuit being responsive only to the output of the second difference amplifier.
Claim 3
Dependent Claim 75 words
A fuel control system as claimed in Claim 1 in which said limit circuit has a control terminal the signal at which determines the limit imposed on the error signal, said control terminal being connected to the output terminal of the second difference amplifier by a lag circuit, which introduces a delay between a change in the output of the second difference amplifier and the corresponding change in the signal applied to the control terminal.

References Cited (Backward Citations)

US3076312A Cited
US3098356A Cited
US3295316A Cited
US3357177A Cited
US3533236A Cited
US3546598A Cited
US3774395A Cited
US3691405A Cited
US3747340A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-12-29 1979-06-30 1979-12-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-12-29 1983-06-30 1983-12-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-12-29 1987-06-30 1987-12-30 $7700.00 Window Closed / Lapsed

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