US3683690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable time constant altitude rate device
Assignee: International Dynamics Corp
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Filing: 1970-07-29
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Granted: 1972-08-15
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Expires: 1990-07-29
Abstract
Abstract A pressure altitude rate indicator is constructed with means for providing variable time constant damping which decreases with increases in altitude rate. Variable time constant damping is achieved by producing a D.C. voltage analog derived from an A.C. voltage analog of the rate at the output of an altitude transducer motor-generator. The D.C. analog is passed through a variable time-constant filter whose variable element is driven by the same servo system that drives the rate display indicator. The output from the variable time constant filter provides one input to the differential amplifier of the display servo. The other input to this differential amplifier is provided by the movable contact of a follow-up potentiometer connected across the output of a D.C. reference voltage source. The parameters of the circuit are selected so that within the most used portion of the range being measured, variations in time constant damping are such that the effect is the same as producing a readout each time there is an altitude change of a predetermined magnitude.
Inventors
- 👤 John H Andresen Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:31
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/62
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
273 words
Apparatus for indicating rate of change for a variable condition; said apparatus including first means acting in response to said variable condition to produce an output of unfiltered rate of change for said variable condition; a variable damping means having an input fed by said output of said first means; an output means; second means fed by said variable damping means and connected to said output means to produce an output thereat of variably damped rate of change for said variable condition; said first means including a transducer having an input connected to detect and respond to changes in said variable condition, and a rate generating means having an input driven by an output of said transducer; said output means including a display device, and servo means fed by output signals generated by said damping means, and driving said display device; said damping means including a variable impedance element, and said servo means controlling the impedance of said impedance element whereby time constant damping of said display device automatically varies in relation to changes in said variable condition which occur over a predetermined range thereof; said output of said rate generating means being a voltage analog of the rate of change being detected by the transducer; said indicator means also including a reference voltage generator, and another damping means having an input fed by said reference voltage generator; said another damping means including another variable impedance element; said servo means also controlling said another impedance element, whereby the output of the reference voltage generator is a voltage that automatically varies in relation to changes in said variable condition occurring in said predetermined range.
Claim 2
Dependent Claim
273 words
Apparatus for indicating rate of change for a variable condition; said apparatus including first means acting in response to said variable condition to produce an output of unfiltered rate of change for said variable condition; a variable damping means having an input fed by said output of said first means; an output means; second means fed by said variable damping means and connected to said output means to produce an output thereat of variably damped rate of change for said variable condition; said first means including a transducer having an input connected to detect and respond to changes in said variable condition, and a rate generating means having an input driven by an output of said transducer; said output means including a display device, and servo means fed by output signals generated by said damping means, and driving said display device; said damping means including a variable impedance element, and said servo means controlling the impedance of said impedance element whereby time constant damping of said display device automatically varies in relation to changes in said variable condition which occur over a predetermined range thereof; said output of said rate generating means being a voltage analog of the rate of change being detected by the transducer; said indicator means also including a reference voltage generator, and another damping means having an input fed by said reference voltage generator; said another damping means including another variable impedance element; said servo means also controlling said another impedance element, whereby the output of the reference voltage generator is a voltage that automatically varies in relation to changes in said variable condition occurring in said predetermined range.
Claim 3
Dependent Claim
21 words
Apparatus as set forth in claim 1, in which the variable condition is pressure altitude and the transducer is pressure responsive.
Claim 4
Dependent Claim
22 words
Apparatus as set forth in claim 2, in which the time constant decreases with increase in the rate of change being indicated.
Claim 5
Dependent Claim
36 words
Apparatus as set forth in claim 1, in which there is a differential amplifier which controls operation of the servo means, by generating signals derived by comparing the outputs of the damping means with one another.
Claim 6
Dependent Claim
21 words
Apparatus as set forth in claim 4, in which the variable condition is pressure altitude and the transducer is pressure responsive.
Claim 7
Dependent Claim
22 words
Apparatus as set forth in claim 5, in which the time constant decreases with increases in the rate of change being indicated.
Claim 8
Dependent Claim
96 words
Apparatus for indicating rate of change of altitude; said apparatus including first means to generate electric signals related to altitude; second means driven by said electric signals and producing signals related to changes in said altitude, at a relatively short rate; output means receiving signals from said second means and producing output signals related to said rate of change at a relatively long time constant that varies as an inverse function of said rate of change; said output signals of said output means being derived from signals produced over a relatively constant interval change in altitude.
Claim 9
Dependent Claim
96 words
Apparatus for indicating rate of change of altitude; said apparatus including first means to generate electric signals related to altitude; second means driven by said electric signals and producing signals related to changes in said altitude, at a relatively short rate; output means receiving signals from said second means and producing output signals related to said rate of change at a relatively long time constant that varies as an inverse function of said rate of change; said output signals of said output means being derived from signals produced over a relatively constant interval change in altitude.
References Cited (Backward Citations)
US3028534A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |