US3576986A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Analog/digital differential apparatus for comparing resolver output data with a digital signal
Assignee: Honeywell Inc
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Filing: 1969-01-14
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Granted: 1971-05-04
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Expires: 1989-01-14
Abstract
Abstract Apparatus for comparing an analog input signal with a digital input signal and providing an analog output signal proportional to the difference therebetween, said apparatus comprising an analog/digital differential controller including digital-toanalog converters responsive to the more significant bits of the digital signal and operating in combination with multiplier and subtractor devices for establishing a coarse relationship between the analog and digital input signals and supplying an accurate reference voltage to a fine resolution digital-to-analog converter which is responsive to the less significant bits of the digital signal to produce fine data for summing with the coarse data and thereby form the output signal.
Inventors
- 👤 David R Brickner
- 👤 Billy K Swift
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:22
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/22; G08; G08C; G08C19/00; G08C19/38; G08C19/46; G08C19/48; H; H03; H03M; H03M1/00; H03M1/12; H03M1/48; H03M1/485
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
268 words
Apparatus for producing an analog output signal proportional to the angular difference between an analog electrical angle input signal and a digital electrical angle input signal comprising: means for receiving the digital input signal and first and second trigonometric functions of the analog input signal, digital-to-analog converter means for producing in response to the digital signal a first pair of trigonometric functions corresponding to a first value of the digital signal and a second pair of trigonometric functions corresponding to a second value of the digital signal, said first and second values being separated by a predetermined amount whereby they may bracket the analog signal, multiplier means for providing a first product signal of the first function of the analog signal and one function of the first pair of trigonometric functions, a second product signal of the second function of the analog signal and the other function of the first pair of trigonometric functions, a third product signal of the first function of the analog signal and one function of the second pair of trigonometric functions, and a fourth product signal of the second function of the analog signal and the other function of the second pair of trigonometric functions, and means for combining the first and second product signals to provide a first difference signal which is a funCtion of the difference between the analog signal and the first value of the digital signal and combining the second and third product signals to provide a second difference signal which is a function of the difference between the analog signal and the second value of the digital signal.
Claim 2
Dependent Claim
268 words
Apparatus for producing an analog output signal proportional to the angular difference between an analog electrical angle input signal and a digital electrical angle input signal comprising: means for receiving the digital input signal and first and second trigonometric functions of the analog input signal, digital-to-analog converter means for producing in response to the digital signal a first pair of trigonometric functions corresponding to a first value of the digital signal and a second pair of trigonometric functions corresponding to a second value of the digital signal, said first and second values being separated by a predetermined amount whereby they may bracket the analog signal, multiplier means for providing a first product signal of the first function of the analog signal and one function of the first pair of trigonometric functions, a second product signal of the second function of the analog signal and the other function of the first pair of trigonometric functions, a third product signal of the first function of the analog signal and one function of the second pair of trigonometric functions, and a fourth product signal of the second function of the analog signal and the other function of the second pair of trigonometric functions, and means for combining the first and second product signals to provide a first difference signal which is a funCtion of the difference between the analog signal and the first value of the digital signal and combining the second and third product signals to provide a second difference signal which is a function of the difference between the analog signal and the second value of the digital signal.
Claim 3
Dependent Claim
99 words
The apparatus of claim 1 wherein: the first product signal is the sine of the analog signal multiplied by the cosine of the first value of the digital signal, the second product signal is the cosine of the analog signal multiplied by the sine of the first value of the digital signal, the third product signal is the sine of the analog signal multiplied by the cosine of the second value of the digital signal and the fourth product signal is the cosine of the analog signal multiplied by the sine of the second value of the digital signal.
Claim 4
Dependent Claim
57 words
The apparatus of claim 2 wherein the digital-to-analog converter means and the multiplier means comprise a plurality of transformers each having a plurality of taps operating in conjunction with tap select logic and switching circuits responsive to the more significant bits of the digital signal for grounding appropriate taps on each transformer to provide the product signals.
Claim 5
Dependent Claim
73 words
The apparatus of claim 3 wherein the converter and multiplier transformers total four in number, the sine function of the analog input signal being applied across the primary winding of two of the transformers with the cosine function of the analog input signal applied across the primary winding of the other two transformers, and the taps positioned so as to generate sine and cosine voltage transformation ratios between the primary and secondary windings.
Claim 6
Dependent Claim
83 words
The apparatus of claim 4 wherein the transformation ratio-controlling taps are connected to the primary windings and are operative to produce a 90* sector of the sine and cosine functions of the digital signal, and the end terminals of the secondary windings of each transformer connect to tap select and logic circuits responsive to the two most significant bits of the digital signal for selectively grounding one of the end terminals to provide quadrant switching such that each transformer is operative through 360*.
Claim 7
Dependent Claim
50 words
The apparatus of claim 5 wherein the combining means comprises two additional transformers having the first and second product signals connected across the primary winding of one of said additional transformers and the third and fourth product signals connected across the primary winding of the other of said additional transformers.
Claim 8
Dependent Claim
34 words
The apparatus of claim 1 and further including means for subtractively combining the first and second difference signals to produce a reference signal having an amplitude which tracks the magnitude of the analog signal.
Claim 9
Dependent Claim
90 words
The apparatus of claim 7 wherein the converter means is responsive to the more significant bits of the digital signal and further including: additional digital-to-analog converter means connected to receive the reference signal and responsive to the less significant bits of the digital signal for selecting a fractional part of said reference signal; and means for algebraically summing the first difference signal and the selected fraction of the reference signal to provide the output signal which is a function of the angular difference between the analog and digital input signals.
Claim 10
Dependent Claim
45 words
The apparatus of claim 8 and further including means for providing the analog and digital input signals, the analog signal providing means comprising an earth''s magnetic field sensitive mechanism responsive to the horizontal component of the earth''s magnetic field for determining directivity with respect thereto.
Claim 11
Dependent Claim
73 words
The apparatus of claim 9 and further including means connected to the earth''s field sensitive mechanism for converting three-wire data, the three-wire data being represented by three signals of equal frequency having cyclically varying amplitudes phase shifted by 120* relative to one another and the two-wire data being represented by two signals which are also functions of said equal frequency and have cyclically varying amplitudes phase shifted by 90* relative to one another.
Claim 12
Dependent Claim
63 words
The apparatus of claim 8 and further including: a phase detector connected to the algebraic summing means to receive the output signal and generate therefrom a control signal whose polarity depends on the relative angular values of the analog and digital input signals; and a digital processor connected to the phase detector to receive the control signal and provide the digital input signal.
Claim 13
Dependent Claim
48 words
The apparatus of claim 11 wherein the digital processor includes an up/down counter whose direction of count is determined by the polarity of the control signal to vary the digital input signal such that it corresponds to the analog input signal whereupon the output signal reduces to zero.
Claim 14
Dependent Claim
65 words
The apparatus of claim 12 and further including a flux valve for determining directivity with respect to the horizontal component of the earth''s magnetic field, and a Scott T transformation device for converting the three-wire flux valve data to equivalent two-wire data represented by sine and cosine functions of the angle between the flux valve axis and the horizontal component of the earth''s magnetic field.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |