US3842676A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Altitude computer apparatus
Assignee: Honeywell Inc
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Filing: 1973-05-03
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Granted: 1974-10-22
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Expires: 1993-05-03
Abstract
Abstract An apparatus including a pressure sensing device in combination with a frequency converter, a displacement servo and a transducer in which the pressure sensing device incorporates a vibrating sensitive diaphragm in combination with an electrical drive circuit and a variable frequency oscillator for producing output voltages having frequencies which vary in a substantially linear manner with respect to pressure altitude. The frequency converter is coupled to the pressure sensing device and has a substantially linear transfer characteristic of variable frequency input with respect to amplitude of voltage output for transforming the variable frequency electrical output signal from the pressure sensing device into a variable amplitude output voltage that is applied to the displacement servo which provides an output shaft angle displacement. The transducer is coupled through appropriate gearing to the displacement servo which produces an output electrical signal in response to the output shaft angle displacement that is linearly proportional to the pressure altitude.
Inventors
- 👤 C Brown
- 👤 R Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:27
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0001; G01L9/0008; G01L9/0016
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
146 words
An aircraft altitude computer comprising sensing means including a variable frequency oscillator coupled to an electrical driving circuit that vibrates a sensitive diaphragm which is responsive to changes in static pressure, said sensing means having a substantially linear transfer characteristic of vibrating frequency versus pressure altitude for producing an electrical output signal that varies in frequency in a substantially linear manner for changes in pressure altitude, converting means having a linear transfer characteristic of variable frequency input versus amplitude of voltage output coupled to said sensing means for transforming said variable frequency electrical output signal into a variable amplitude voltage, displacement servo means coupled to said converter means for providing an output shaft angle displacement in response to said variable amplitude direct current voltage, and transducer means responsive to said output shaft angle displacement for producing electrical output signals respresentative of said changes in pressure altitude.
Claim 2
Dependent Claim
146 words
An aircraft altitude computer comprising sensing means including a variable frequency oscillator coupled to an electrical driving circuit that vibrates a sensitive diaphragm which is responsive to changes in static pressure, said sensing means having a substantially linear transfer characteristic of vibrating frequency versus pressure altitude for producing an electrical output signal that varies in frequency in a substantially linear manner for changes in pressure altitude, converting means having a linear transfer characteristic of variable frequency input versus amplitude of voltage output coupled to said sensing means for transforming said variable frequency electrical output signal into a variable amplitude voltage, displacement servo means coupled to said converter means for providing an output shaft angle displacement in response to said variable amplitude direct current voltage, and transducer means responsive to said output shaft angle displacement for producing electrical output signals respresentative of said changes in pressure altitude.
Claim 3
Dependent Claim
146 words
An aircraft altitude computer as recited in claim 1 in which said sensing means includes an enclosure which contains a sensitive diaphragm secured to said enclosure at its peripheral edge for sub-dividing said enclosure into a first compartment having means for receiving a fluid at static pressure and a second compartment having means for maintaining a reference vacuum pressure, electrical driving means associated with said diaphragm for vibrating said diaphragm at its resonant frequency which varies in accordance with the value of said static pressure at respective pressure altitudes, and variable frequency oscillator means coupled to said driving means, said driving means forming in part the tuning circuit for said oscillator means and receiving the current output of said oscillator means in closed loop fashion for producing an electrical output signal that varies in frequency in a substantially linear manner for changes in said pressure altitude.
Claim 4
Dependent Claim
45 words
An altitude computer as recited in claim 2 in which said converter means includes a frequency to voltage converter coupled to said oscillator means for producing a variable amplitude output direct current voltage that is a substantially linear function of said changes in pressure altitude.
Claim 5
Dependent Claim
53 words
An altitude computer as recited in claim 1 in which said displacement servo means includes a summing element having a first input terminal connected to said converter means and a second input terminal connected to a feed back potentiometer for providing a difference error signal in accordance with said variable amplitude output voltage.
Claim 6
Dependent Claim
48 words
An altitude computer as recited in claim 1 in which said displacement servo means includes a motor for providing an output shaft angle displacement and said transducer means includes synchros responsive to said output shaft angle displacement for producing electrical signals representative of said changes in pressure altitude.
Claim 7
Dependent Claim
30 words
An altitude computer as described in claim 5 in which said transducer means includes coarse and fine synchros for providing electrical output signals representative of said changes in pressure altitude.
Claim 8
Dependent Claim
58 words
An altitude computer as recited in claim 5 in which said displacement servo means further includes a summing element, an amplifier, a direct current motor and a gear train connected in series and a feedback potentiometer positioned by said gear train to provide a feedback voltage to said summing element that represents the position of said gear train.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |