Patent US3789393A successfully refreshed from Google Patents.
US3789393A
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Digital/analog converter with amplitude and pulse-width modulation
Assignee: Inductosyn Corp
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Filing: 1972-10-26
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Granted: 1974-01-29
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Expires: 1992-10-26
Abstract
Abstract Disclosed is a digital-to-analog position-measuring apparatus in which the position-measuring transducer is energized by a combination of differently modulated signals. In one preferred embodiment of the present invention, trigonometrically related (sine-cosine) pulse-width modulated signals are trigonometrically summed with pulse-amplitude modulated signals. The pulseamplitude modulated signals comprise the fine bits and the pulsewidth modulated signals comprise the coarse bits of the apparatus of the preferred embodiment of the present invention.
Inventors
- 👤 R Tripp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:26
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/204; G01D5/2073; G01D5/208; H; H03; H03M; H03M1/00; H03M1/66; H03M1/68; H03M1/82
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
122 words
In the method of providing an output pulse train having a frequency component with an amplitude and a phase representative of a trigonometric function of an angle, the steps of: apportioning said angle into a fine portion and a coarse portion; generating a first train of pulses at a carrier frequency wherein each pulse has a duration which is a first function of said coarse portion; generating a second train of pulses at said carrier frequency wherein each pulse has a duration which is a second function of said coarse portion and has an amplitude which is a function of said fine portion; and algebraically combining said first and second pulse trains, thereby providing said output pulse train at said carrier frequency.
Claim 2
Dependent Claim
122 words
In the method of providing an output pulse train having a frequency component with an amplitude and a phase representative of a trigonometric function of an angle, the steps of: apportioning said angle into a fine portion and a coarse portion; generating a first train of pulses at a carrier frequency wherein each pulse has a duration which is a first function of said coarse portion; generating a second train of pulses at said carrier frequency wherein each pulse has a duration which is a second function of said coarse portion and has an amplitude which is a function of said fine portion; and algebraically combining said first and second pulse trains, thereby providing said output pulse train at said carrier frequency.
Claim 3
Dependent Claim
151 words
The method of claim 1 for providing a sine output pulse train having a carrier frequency component which has an amplitude proportional to the sine of said angle and has a phase representative of the sign of the sine of said angle, wherein: the step of generating said first pulse train includes generating a carrier frequency component thereof having an amplitude proportional to the sine of said coarse portion and having a phase representative of the sign of the sine of said coarse portion; the step of generating said second pulse train includes generating a carrier frequency component thereof having an amplitude proportional to a cosine product which is the product of a function of said fine portion and the cosine of said coarse portion and having a phase representative of the sign of said cosine product; and said combining step is a summation thereby providing said sine output pulse train.
Claim 4
Dependent Claim
28 words
The method of claim 2 wherein the step of generating said second pulse train includes generating pulses having an amplitude proportional to the tangent of said fine portion.
Claim 5
Dependent Claim
47 words
The method of claim 2 wherein the step of apportioning includes apportioning said angle to substantially cause an equality between said fine portion and the tangent thereof, and the step of generating said second pulse train includes generating pulses having an amplitude proportional to said fine portion.
Claim 6
Dependent Claim
151 words
The method of claim 1 for providing a cosine output pulse train Having a carrier frequency component which has an amplitude proportional to the cosine of said angle and has a phase representative of the sign of the cosine of said angle wherein: the step of generating said first pulse train includes generating a carrier frequency component thereof having an amplitude proportional to the cosine of said coarse portion and having a phase representative of the sign of the cosine of said coarse portion; the step of generating said second pulse train includes generating a carrier frequency component thereof having an amplitude proportional to a sine product which is the product of a function of said fine portion and the sine of said coarse portion and having a phase representative of the sign of said sine product; and said combining step is a subtraction, thereby providing said cosine output pulse train.
Claim 7
Dependent Claim
28 words
The method of claim 5 wherein the step of generating said second pulse train includes generating pulses having an amplitude proportional to the tangent of said fine portion.
Claim 8
Dependent Claim
47 words
The method of claim 5 wherein the step of apportioning includes apportioning said angle to substantially cause an equality between said fine portion and the tangent thereof, and the step of generating said second pulse train includes generating pulses having an amplitude proportional to said fine portion.
Claim 9
Dependent Claim
189 words
In a digital-to-analog converter which receives signals representative of a change of an angle, a pulse-amplitude control and a pulse-width control provide respective signal representations of a fine portion and a coarse portion of said angle, a clock pulse source provides clock pulses to pulse-width modulator which is connected to said pulse-width control, said modulator provides a first train of pulses at a carrier frequency, each pulse thereof having a duration which is a first function of said coarse portion; the improvement comprising: generating means connected to said controls and said clock source for generating a second train of pulses at said carrier frequency, each pulse thereof having a duration which is a second function of said coarse portion and having an amplitude which is proportional to said fine portion; and means connected to said pulse-width modulator and said generating means for providing an algebraic combination of the amplitudes of respective pulses of said first and second pulse trains, a carrier frequency component of said algebraic combination having an amplitude proportional to a trigonometric function of said angle and having a phase representative of the sign of said function.
Claim 10
Dependent Claim
189 words
In a digital-to-analog converter which receives signals representative of a change of an angle, a pulse-amplitude control and a pulse-width control provide respective signal representations of a fine portion and a coarse portion of said angle, a clock pulse source provides clock pulses to pulse-width modulator which is connected to said pulse-width control, said modulator provides a first train of pulses at a carrier frequency, each pulse thereof having a duration which is a first function of said coarse portion; the improvement comprising: generating means connected to said controls and said clock source for generating a second train of pulses at said carrier frequency, each pulse thereof having a duration which is a second function of said coarse portion and having an amplitude which is proportional to said fine portion; and means connected to said pulse-width modulator and said generating means for providing an algebraic combination of the amplitudes of respective pulses of said first and second pulse trains, a carrier frequency component of said algebraic combination having an amplitude proportional to a trigonometric function of said angle and having a phase representative of the sign of said function.
Claim 11
Dependent Claim
127 words
Apparatus according to claim 8 wherein said algebraic combination includes a carrier frequency component having an amplitude proportional to the sine of said angle and having a phase representative of the sign of the sine of said angle, and said first pulse train includes a carrier frequency component having an amplitude proportional to the sine of said coarse portion and having a phase representative of the sign of the sine of said coarse portion, said generating means comprising: means for generating said second pulse train with a carrier frequency component having an amplitude which is proportional to a cosine product which is the product of said fine portion and the cosine of said coarse portion and having a phase representative of the sign of said cosine product.
Claim 12
Dependent Claim
127 words
Apparatus according to claim 8 wherein said algebraic combination includes a carrier frequency component having an amplitude proportional to the cosine of said angle and having a phase representative of the sign of the cosine of said angle, and said first pulse train includes a carrier frequency component having an amplitude proportional to the cosine of said coarse portion and having a phase representative of the sign of the cosine of said coarse portion, said generating means comprising: means for generating said second pulse train with a carrier frequency component having an amplitude which is proportional to a sine product whiCh is the product of said fine portion and the sine of said coarse portion and having a phase representative of the sign of said sine product.
References Cited (Backward Citations)
US3324376A
Cited
US3446992A
Cited
US3596200A
Cited
US3621354A
Cited
US3668560A
Cited
US3706943A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |