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US3576561A
Expired / Lapsed
US
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Digital-analogue converters
Assignee: Alcatel Lucent SAS
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Filing: 1967-01-23
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Granted: 1971-04-27
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Expires: 1987-01-23
Abstract
Abstract A converter of the digital-analogue-type for producing analogue voltages having a predetermined nonlinear characteristic in which digital switches operated in binary coded format provide signals for selectively connecting different ones of a plurality of weighted resistances to a reference voltage source in response to signals from the several digital switches and to signals from the outputs of logic AND elements each having an input connected to a digital switch of a given rank and an input connected to a digital switch of higher rank, there being one resistance for each digital switch and one for each logic AND circuit. The output ends of the weighted resistances are connected to a common output terminal to provide output voltages of a predetermined nonlinear characteristic which may be utilized as such or connected to a comparator for feeding signals back to the digital switches for translating nonlinear voltages to be measured into a digital indication. In one embodiment, the number of logic AND elements associated with each digital switch corresponds to the number of digital switches of a higher rank whereby a logic AND element of each switch except that of highest rank is connected to each of the switches of higher rank.
Inventors
- 👤 Gabriel Henri Leon Dureau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:27
CPC Classifications
H; H04; H04B; H04B14/00; H04B14/02; H04B14/04; H04B14/046; H04B14/048; H03; H03M; H03M1/00; H03M1/12; H03M1/34; H03M1/38; H03M1/42
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
293 words
In a converter of the digital-analogue type for producing analogue voltages having a nonlinear characteristic, the combination of means including a plurality of at least four digital switches for providing successive signals in progressive binary coded format, a plurality of logic AND element means associated with each of said digital switches except that of highest rank, the number of logic AND elements associated with each switch of given rank being equal to the number of digital switches of a higher rank, each of said logic AND elements having two input terminals, means for connecting each of said digital switches except that of highest rank to an input terminal of each of its associated logic AND elements, means for connecting the other input terminals of the respective logic AND elements associated with each digital switch of a lower rank to a different digital switch of a higher rank, a resistance network comprising a plurality of weighted resistances connected at their output ends to a common output terminal, there being one resistance associated with each digital switch and a separate resistance associated with each logic AND element, a source of reference voltage, means including a switch means directly connected between the input ends of each of said first named resistances and its associated digital switch for normally connecting said inputs to ground and selectively connecting the inputs to said reference voltage in response to a signal from the digital switch, and means including a switch means directly connected between the input ends of each of said second named resistances and the output of its associated logic AND elements for normally connecting said inputs to ground and selectively connecting the inputs to said reference voltage in response to an output signal from the logic AND element.
Claim 2
Dependent Claim
293 words
In a converter of the digital-analogue type for producing analogue voltages having a nonlinear characteristic, the combination of means including a plurality of at least four digital switches for providing successive signals in progressive binary coded format, a plurality of logic AND element means associated with each of said digital switches except that of highest rank, the number of logic AND elements associated with each switch of given rank being equal to the number of digital switches of a higher rank, each of said logic AND elements having two input terminals, means for connecting each of said digital switches except that of highest rank to an input terminal of each of its associated logic AND elements, means for connecting the other input terminals of the respective logic AND elements associated with each digital switch of a lower rank to a different digital switch of a higher rank, a resistance network comprising a plurality of weighted resistances connected at their output ends to a common output terminal, there being one resistance associated with each digital switch and a separate resistance associated with each logic AND element, a source of reference voltage, means including a switch means directly connected between the input ends of each of said first named resistances and its associated digital switch for normally connecting said inputs to ground and selectively connecting the inputs to said reference voltage in response to a signal from the digital switch, and means including a switch means directly connected between the input ends of each of said second named resistances and the output of its associated logic AND elements for normally connecting said inputs to ground and selectively connecting the inputs to said reference voltage in response to an output signal from the logic AND element.
Claim 3
Dependent Claim
97 words
In a converter as set forth in claim 1, in which said means including a plurality of digital switches of at least four for providing successive signals in progressive binary coded format, said first-mentioned means including a switch means, comprises means for selectively connecting said first-named resistances to said reference voltage in direct response to a signal from the associated digital switches, and in which said second-mentioned means including a switch means comprises means for selectively connecting said second-named resistances to said reference voltage solely in response to an output signal from their associated logic AND elements.
Claim 4
Dependent Claim
62 words
A converter as set froth in claim 2 in which a separate switch means connected to the input side of each of said resistances of said resistance network and operable in response to an output signal from the respective digital switches and logic AND elements associated with said resistances provides for selectively connecting the resistances to ground or to said reference voltage.
Claim 5
Dependent Claim
44 words
A converter as set forth in claim 2 in which said common output terminal is connected to a low value resistance having its other end connected to ground thereby to provide a series of analogue voltages at said terminal having a predetermined nonlinear characteristic.
Claim 6
Dependent Claim
43 words
A converter as set forth in claim 2 in which means is provided fOr connecting said common output terminal to a voltage to be measured and to a comparator means, and means operated by said comparator means provides for gating said digital switches.
Claim 7
Dependent Claim
76 words
A converter as set forth in claim 2 in which there is provided for each digital switch a number of associated logic AND elements corresponding to the number of higher ranking digits, each digital switch is directly connected to one of the inputs of its associated logic AND elements, and each digital switch of higher rank is directly connected to the other input of a logic AND element associated with each digital switch of lower rank.
Claim 8
Dependent Claim
64 words
A converter as set forth in claim 2 in which an input of at least one of said logic AND elements is connected to a complement of a digit of higher rank, and an input of another of said logic AND elements is connected through a logic ''''ADDER'''' means to said digit of higher rank and the complement of another digit of higher rank.
References Cited (Backward Citations)
US3015815A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-04-26 | 1974-10-26 | 1975-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-04-26 | 1978-10-26 | 1979-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-04-26 | 1982-10-26 | 1983-04-27 | $7700.00 | Window Closed / Lapsed |