Patent US3843877A successfully refreshed from Google Patents.
US3843877A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air data computer including dc to synchro signal converter
Assignee: Honeywell Inc
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Filing: 1973-02-06
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Granted: 1974-10-22
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Expires: 1993-02-06
Abstract
Abstract A vibratory type air data sensor, for example an altitude sensor, provides an output signal having a frequency which varies in accordance with altitude, which output in turn is converted into a d.c. signal which varies proportionally with altitude. The ratio of this variable d.c. voltage to a reference d.c. voltage is converted to a time period ratio by utilizing an oscillator to generate a reference a.c. time base and a counter and integrator means for determining the time period ratioed with the reference time base. This time period ratio is used to sample the oscillator to obtain signals proportional to the sine and cosine values of the a.c. time base which may then be converted to conventional resolver or three-wire synchro signal altitude data. A second oscillator, controlled by the counter means and having a frequency which bears a predetermined ratio to the timing oscillator may also be sampled by the time period ratio and the sine and cosine values thereof converted to conventional resolver format or three-wire synchro signal format bearing said ratio to the first synchro signal output. Fine and coarse synchro signal altitude data is thus obtained. Further, counter means synchronized to the reference oscillator and the first mentioned counter is employed to provide digital data proportional to the variable d.c. altitude signal for conversion to altitude reporting signal format.
Inventors
- 👤 P Roselle
- 👤 D Evans
- 👤 V Bussma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:31
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/22
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
134 words
Apparatus for converting a variable direct current signal to a corresponding sine/cosine signal format comprising, means for providing said variable direct current signal, oscillator means for providing a reference a.c. time base signal, means providing a reference d.c. signal, integrator means, counter means responsive to said reference a.c. signal for alternately supplying said variable d.c. signal and said reference d.c. signal to said integrator means in opposite senses for predetermined substantially equal time periods and for providing a sampling pulse at a time period corresponding to the ratio of said d.c. signal voltages, and sample and hold means responsive to said time base a.c. signal and said sampling pulse for supplying d.c. signals proportional respectively to the instantaneous sine and cosine values of said voltage ratio and hence proportional to said variable d.c. signal.
Claim 2
Dependent Claim
134 words
Apparatus for converting a variable direct current signal to a corresponding sine/cosine signal format comprising, means for providing said variable direct current signal, oscillator means for providing a reference a.c. time base signal, means providing a reference d.c. signal, integrator means, counter means responsive to said reference a.c. signal for alternately supplying said variable d.c. signal and said reference d.c. signal to said integrator means in opposite senses for predetermined substantially equal time periods and for providing a sampling pulse at a time period corresponding to the ratio of said d.c. signal voltages, and sample and hold means responsive to said time base a.c. signal and said sampling pulse for supplying d.c. signals proportional respectively to the instantaneous sine and cosine values of said voltage ratio and hence proportional to said variable d.c. signal.
Claim 3
Dependent Claim
38 words
The apparatus as set forth in claim 1 further including modulator means responsive to said d.c. sine and cosine signals for providing amplitude modulated a.c. signals proportional to said sine and cosine values of said variable d.c. signal.
Claim 4
Dependent Claim
31 words
The apparatus as set forth in claim 1 wherein said oscillator means provides sine and cosine signals of like periods and said counter means is responsive to one of said signals.
Claim 5
Dependent Claim
35 words
The apparatus as set forth in claim 1 wherein said integrator means includes zero crossover detector means responsive to the output thereof, said sample pulse being generated when the output of said integrator is zero.
Claim 6
Dependent Claim
81 words
The apparatus as set forth in claim 1 further including, second oscillator means responsive to said counter means and having a frequency proportionally related to said reference oscillator means, and further sample and hold means responsive to said sampling pulse and said second oscillator means for providing second d.c. signals proportional respectively to the instantaneous sine and cosine values of said voltage ratio whereby said second sine and cosine values bear said predetermined ratio to said first mentioned sine cosine values.
Claim 7
Dependent Claim
37 words
The apparatus as set forth in claim 5 further including second modulator means responsive to said second d.c. sine and cosine signals for converting the same to a.c. signals proportionally related to said first mentioned a.c. signals.
Claim 8
Dependent Claim
111 words
Apparatus for converting a variable direct current signal to a corresponding alternating current sine/cosine signal format comprising, a source of variable d.c. voltage signal to be converted, a source of reference d.c. voltage signal, oscillator means for providing a reference time base, means responsive to the ratio of said variable to said reference d.c. voltage signals and controlled by said oscillator means for converting said voltage ratio to a time period ratio, and means responsive to said time period ratio for sampling said oscillator whereby to provide signals proportional at that instant to the sine and cosine values of said oscillator time base and hence proportional to said variable d.c. signAl.
Claim 9
Dependent Claim
111 words
Apparatus for converting a variable direct current signal to a corresponding alternating current sine/cosine signal format comprising, a source of variable d.c. voltage signal to be converted, a source of reference d.c. voltage signal, oscillator means for providing a reference time base, means responsive to the ratio of said variable to said reference d.c. voltage signals and controlled by said oscillator means for converting said voltage ratio to a time period ratio, and means responsive to said time period ratio for sampling said oscillator whereby to provide signals proportional at that instant to the sine and cosine values of said oscillator time base and hence proportional to said variable d.c. signAl.
Claim 10
Dependent Claim
30 words
The apparatus as set forth in claim 7 further including modulator means responsive to said sine and cosine values for converting the same to an alternating current synchro signal format.
Claim 11
Dependent Claim
59 words
The converter apparatus as set forth in claim 7 wherein said voltage ratio to time period ratio converting means comprises integrator means and means controlled by said oscillator means for alternately supplying said variable and reference d.c. voltages thereto in opposite senses, the instant the output of said integrator returns to zero being proportional to said time period ratio.
Claim 12
Dependent Claim
21 words
The apparatus as set forth in claim 9 wherein said sampling means is responsive to the output of said integrator means.
Claim 13
Dependent Claim
45 words
The apparatus as set forth in claim 10 wherein said oscillator means provides a reference sine wave signal and a cosine wave signal, and wherein said sampling means samples the instantaneous value of said sine and cosine waves to provide d.c. voltages respectively proportional thereto.
Claim 14
Dependent Claim
47 words
The apparatus as set forth in claim 8 wherein said converter means responsive to said d.c. sine and cosine voltages comprises modulator means responsive thereto and further means responsive to the alternating sine/cosine outputs of said modulator means for converting the same to three-wire synchro signal format.
Claim 15
Dependent Claim
163 words
Variable direct current to sine/cosine signal converter apparatus comprising, means for providing said direct current signal variable over a range of values, oscillator means for providing reference sine and cosine a.c. signals, means providing a reference d.c. signal having a magnitude corresponding to the maximum of said range of values, integrator means, counter means responsive to one of said oscillator signals for supplying said variable d.c. signal in a first sense to said integrator means for a period corresponding to said maximum range and for thereafter supplying said reference d.c. signal to said integrator means in an opposite sense for a substantially like period, zero crossing detector means responsive to the output of said integrator means for supplying a signal upon return of said integrator output to zero, and means responsive to said reference sine and cosine signals and to said zero crossing detector signal for providing d.c. signals respectively proportional to the instantaneous values of said sine and cosine signals then obtaining.
Claim 16
Dependent Claim
163 words
Variable direct current to sine/cosine signal converter apparatus comprising, means for providing said direct current signal variable over a range of values, oscillator means for providing reference sine and cosine a.c. signals, means providing a reference d.c. signal having a magnitude corresponding to the maximum of said range of values, integrator means, counter means responsive to one of said oscillator signals for supplying said variable d.c. signal in a first sense to said integrator means for a period corresponding to said maximum range and for thereafter supplying said reference d.c. signal to said integrator means in an opposite sense for a substantially like period, zero crossing detector means responsive to the output of said integrator means for supplying a signal upon return of said integrator output to zero, and means responsive to said reference sine and cosine signals and to said zero crossing detector signal for providing d.c. signals respectively proportional to the instantaneous values of said sine and cosine signals then obtaining.
Claim 17
Dependent Claim
28 words
The converter apparatus as set forth in claim 13 further including modulator means responsive to said d.c. sine and cosine signals for providing corresponding amplitude modulated a.c. signals.
Claim 18
Dependent Claim
26 words
The converter apparatus set forth in claim 14 further including circuit means responsive to said a.c. signals for converting the same to three-wire synchro signal format.
Claim 19
Dependent Claim
26 words
The converter apparatus as set forth in claim 13 wherein said counter period corresponds to a predetermined number of cycles of one of said oscillator signals.
Claim 20
Dependent Claim
98 words
The converter apparatus as set forth in claim 13 further including, second oscillator means for providing second sine and cosine a.c. signals bearing a predetermined frequency ratio to said first mentioned oscillator means, means responsive to said counter means for synchronizing said second oscillator means to said first oscillator means, and means responsive to said sine and cosine a.c. signals and said zero crossing detector signal for providing second d.c. signals respectively proportional to the instantaneous values of said sine and cosine signals then obtaining and bearing said predetermined ratio to said first mentioned sine and cosine signals.
Claim 21
Dependent Claim
90 words
The converter apparatus as set forth in claim 13 further including means for converting said variable d.c. signal to a digital format, said further means comprising, second oscillator means, digital counter means responsive to said second oscillator means, means responsive to said first mentioned oscillator means and said counter means for synchronizing saiD second oscillator means to said first oscillator means, and latching means responsive to said zero crossing detector signal for latching said digital counter means, the count then obtaining corresponding to the value of said variable d.c. signal.
Claim 22
Dependent Claim
35 words
The converter apparatus as set forth in claim 18 wherein said second oscillator is synchronized to said first oscillator during said first mentioned period and said digital counter is latched during said second mentioned period.
Claim 23
Dependent Claim
205 words
An all solid state altimeter apparatus for aircriaft comprising, an altitude sensor means for providing a variable frequency signal proportional to instantaneous altitude, means for converting said variable frequency signal to a corresponding variable direct current signal, oscillator means providing reference sine and cosine alternating signals, one of said a.c. signals having a predetermined number of cycles corresponding to a predetermined total altitude range, means providing a reference d.c. signal having a magnitude corresponding to the maximum of said altitude range, integrator means, counter means responsive to said one oscillator signal for supplying said variable d.c. signal in a first sense to said integrator means for said number of cycles and thereafter supplying said reference d.c. signal in an opposite sense to said integrator means for substantially the same number of cycles, zero crossing detector means responsive to the output of said integrator means for supplying a signal upon return of said integrator output to null, means responsive to said reference sine and cosine signals and said zero crossing detector signal for providing d.c. signals respectively proportional to the instantaneous values of said d.c. signal and cosine signals then obtaining, said last mentioned signals being proportional to the sine and cosine values of aircraft altitude.
Claim 24
Dependent Claim
205 words
An all solid state altimeter apparatus for aircriaft comprising, an altitude sensor means for providing a variable frequency signal proportional to instantaneous altitude, means for converting said variable frequency signal to a corresponding variable direct current signal, oscillator means providing reference sine and cosine alternating signals, one of said a.c. signals having a predetermined number of cycles corresponding to a predetermined total altitude range, means providing a reference d.c. signal having a magnitude corresponding to the maximum of said altitude range, integrator means, counter means responsive to said one oscillator signal for supplying said variable d.c. signal in a first sense to said integrator means for said number of cycles and thereafter supplying said reference d.c. signal in an opposite sense to said integrator means for substantially the same number of cycles, zero crossing detector means responsive to the output of said integrator means for supplying a signal upon return of said integrator output to null, means responsive to said reference sine and cosine signals and said zero crossing detector signal for providing d.c. signals respectively proportional to the instantaneous values of said d.c. signal and cosine signals then obtaining, said last mentioned signals being proportional to the sine and cosine values of aircraft altitude.
Claim 25
Dependent Claim
97 words
The altimeter as set forth in claim 20 further including, second oscillator means responsive to said counter means for providing second sine and cosine signals bearing a predetermined ratio to said reference sine and cosine signals, and means responsive to said second sine and cosine signals and said zero crossing detector signal for providing d.c. signals respectively proportional to the instantaneous values of said second sine and cosine signals then obtaining, and one of said sets of sine and cosine signals constituting a fine measure of altitude and the other set constituting a coarse measure of altitude.
Claim 26
Dependent Claim
117 words
The altimeter as set forth in claim 20 further including means for providing a signal proportional to altitude in digital format, said further means comprising, second oscillator means, digital counter means responsive to said second oscillator means, means responsive to said first mentioned oscillator means, said first mentioned counter means, and said digital counter means for synchronizing said second oscillator means to said first oscillator means during said first number of cycles, means responsive to said first counter means for resetting said digital counter means at the start of said second number of cycles, and means responsive to said zero crossing detector signal for latching said digital counter means, the count then obtaining corresponding to aircraft altitude.
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) | 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 |