US3586839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interpolative function generator having a pair of digital-to-analog converters connected in summing relation
Assignee: Individual
•
Filing: 1969-04-25
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Granted: 1971-06-22
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Expires: 1989-04-25
Abstract
Abstract The disclosure concerns a function generator as used in an analog computer and employing a pair of digital to analog converters having outputs connected in summing relation; and circuit means connected with the converters to drive the output of one converter back and forth between function and reference values, and further characterized in that the output of one converter increases while the output of the other converter decreases, and vice versa.
Inventors
- 👤 Gilbert R Grado
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:35
CPC Classifications
G; G06; G06J; G06J1/00; G06G; G06G7/00; G06G7/12; G06G7/30
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
190 words
In a function generator, the combination comprising a. a pair of digital to analog converters having outputs operatively connected in summed relation, and b. circuit means connected with the converters to drive the output of one converter back and forth between reference and function values and simultaneously to drive the output of the other converter back and forth between function and reference values, and further characterized in that the output of one converter increases while the output of the other converter decreases and vice versa, c. each converter including parallel branches in each of which switchable resistance is connected, the circuit means including a source to supply a first sawtooth input to the branches of said one converter and a second sawtooth input to the branches of the other converter, said sawtooth inputs being opposite in phase, and digital means to controllably switch resistance in said branches of one converter when the sawtooth input to the branches of the other converter is approximately peaking, and to controllably switch resistance in said branches of the other converter when the sawtooth input to the branches of said one converter is approximately peaking.
Claim 2
Dependent Claim
190 words
In a function generator, the combination comprising a. a pair of digital to analog converters having outputs operatively connected in summed relation, and b. circuit means connected with the converters to drive the output of one converter back and forth between reference and function values and simultaneously to drive the output of the other converter back and forth between function and reference values, and further characterized in that the output of one converter increases while the output of the other converter decreases and vice versa, c. each converter including parallel branches in each of which switchable resistance is connected, the circuit means including a source to supply a first sawtooth input to the branches of said one converter and a second sawtooth input to the branches of the other converter, said sawtooth inputs being opposite in phase, and digital means to controllably switch resistance in said branches of one converter when the sawtooth input to the branches of the other converter is approximately peaking, and to controllably switch resistance in said branches of the other converter when the sawtooth input to the branches of said one converter is approximately peaking.
Claim 3
Dependent Claim
71 words
The combination of claim 1 wherein the summed output of the converters is approximately defined by the equation where, (Xe-X) Delta X corresponds to the first sawtooth input, (Xo-X)/ Delta X corresponds to the second sawtooth input, Yodd corresponds to the equivalent resistance of said one converter to which said first sawtooth is applied Yeven corresponds to the equivalent resistance of the other converter to which said second sawtooth is applied.
Claim 4
Dependent Claim
95 words
The combination of claim 1 wherein said source includes first and second circuit legs to supply in-phase sawtooth inputs containing out-of-phase switching transients, and said legs being connected to a junction via switches alternately operable to pass sawtooth input from one leg to said junction when the sawtooth inputs from the other leg is disconnected from the junction and is undergoing a switching transient, and to pass sawtooth input from the other leg to said junction when the sawtooth input from said one leg is disconnected from the junction and is undergoing a switching transient.
Claim 5
Dependent Claim
69 words
The combination of claim 3 wherein the source includes amplifier and digital to analog converter elements operatively connected to said legs to produce a signal Xe-X/ Delta X in the first leg and a signal Xo- Delta X/ Delta X in the second leg, where Xo a stored signal Xe a stored signal different from Xo X input signal that varies between Xo and Xe, and Delta X Xe-Xo
Claim 6
Dependent Claim
28 words
The combination of claim 2 including means to adjust the value of Yodd when X reaches Xo and to adjust the value of Yeven when X reaches Xe.
Claim 7
Dependent Claim
59 words
The combination of claim 5 wherein said last named means includes comparator apparatus to sense excursions of X to the values Xo and Xe, a source of stored data values corresponding to function values aNd means responsive to the comparator output to effect selective active connection of converter resistances in converter biasing relation in correspondence with selected data values.
Claim 8
Dependent Claim
15 words
The combination of claim 6 wherein said source of data values includes a punched card.
Claim 9
Dependent Claim
23 words
The combination of claim 4 wherein the summed output of the converters is approximately defined by the equation for Eo of claim 4.
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) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |