US3896431A
Expired / Lapsed
US
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Analogue-to-digital converters
Assignee: Pye Electronic Products Ltd
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Filing: 1973-11-15
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Granted: 1975-07-22
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Expires: 1993-11-15
Abstract
Abstract An analogue-to-digital converter of the dual slope integration type has an integrator portion and analogue input signal of one polarity and a reference signal of opposite polarity, the two signals being alternately connected to the integrator portion. The invention includes means for generating a variable reference signal, the magnitude of which is varied in dependence on the magnitude of the analogue input signal, for producing a predetermined non-linear relationship between the analogue input and the digital output of the converter.
Inventors
- 👤 Brian Arthur Leonard Dickinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:02
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/10; H03M1/1009
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
91 words
In an analogue-to-digital converter of the dual slope integration type having an integrator portion, an analog input signal of one polarity, a reference signal of opposite polarity being supplied thereto and including means for alternately connecting said input signal and reference signal to said integrator portion, said improvement comprising: means for generating a variable reference signal, the magnitude of said variable reference signal being varied in dependence on the magnitude of the analogue input signal, for producing a predetermined non-linear relationship between the analogue and the digital output of the converter.
Claim 2
Dependent Claim
91 words
In an analogue-to-digital converter of the dual slope integration type having an integrator portion, an analog input signal of one polarity, a reference signal of opposite polarity being supplied thereto and including means for alternately connecting said input signal and reference signal to said integrator portion, said improvement comprising: means for generating a variable reference signal, the magnitude of said variable reference signal being varied in dependence on the magnitude of the analogue input signal, for producing a predetermined non-linear relationship between the analogue and the digital output of the converter.
Claim 3
Dependent Claim
98 words
An analogue-to-digital converter according to claim 1 in which said means includes a first means for deriving a first signal from the analogue signal such that the ratio of the magnitude of the first signal to the magnitude of the analogue signal bears one of a plurality of fixed numerical values, one of said values being selected in dependence on the magnitude of the analogue signal, further including a second means which supplies a constant reference signal and a summation unit for summing the first signal with the constant reference signal to provide the said variable reference signal.
Claim 4
Dependent Claim
79 words
An analogue-to-digital converter according to claim 2 wherein the means for deriving the said first signal comprises a potential dividing network including a plurality of resistors each in series with a respective one of a corresponding plurality of switches, each of the switches being adapted to connect its corresponding resistor to the network so as to modify the dividing ratio of the latter when the output from the network attains a predetermined level uniquely associated with the said switch.
Claim 5
Dependent Claim
33 words
An analogue-to-digital converter according to claim 3 wherein each switch comprises a transistor and wherein the said predetermined level is determined by an appropriate bias voltage applied to the base of the transistor.
Claim 6
Dependent Claim
27 words
An analogue-to-digital converter according to claim 1 including means for controlling the polarity of the reference signal in dependence upon the polarity of the analogue input signal.
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) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |