US4243974A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wide dynamic range analog to digital converter
Assignee: EIDP Inc
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Filing: 1978-02-24
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Granted: 1981-01-06
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Expires: 1998-02-24
Abstract
Abstract The conversion of an analog signal which varies over a wide dynamic range, to digital form is accomplished by integrating the analog signal and, simultaneously therewith, integrating in a sense opposite that of the analog signal a reference signal of sufficient amplitude, to maintain the stored charge within the integrator at a relatively low nominal value. This is accomplished by placing comparators on the output of the integrator which function to cause a counter to count up or down in accordance with the relative amplitudes of the analog and reference signals as is necessary to bring the stored charge in the integrator back to the low nominal value. The output of this counter is applied to a range decoder which applies selected geometrically varying ranges of digital signals to a digital to analog converter. The output of the digital to analog converter is applied both to the subtracting or negative input of the integrator, and also provides a reference signal for the comparator. By controlling the time period of each integration and counting the amount of stored energy removed from the integrator, the counter output which is related to the such removed stored energy, is the digital equivalent of the analog signal.
Inventors
- 👤 Rodney L. Mack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:27
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/06; H03M1/0602; H03M1/0604
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
113 words
A method of geometrically converting an input analog signal to an output signal comprising the steps of: integrating said input signal in a first sense to provide an integrating signal, simultaneously therewith integrating a reference signal in a second sense opposite said first sense to reduce the amplitude of said integrated signal, periodically comparing the amplitudes of said integrated and reference signals, geometrically adjusting a digital signal according to each comparison, converting each said adjusted digital signal to analog form to provide said reference signal, and totalizing, over a predetermined measuring interval, the values of each said adjusted digital signal at the time of each comparison, thus to provide said output digital signal.
Claim 2
Independent Claim
113 words
A method of geometrically converting an input analog signal to an output signal comprising the steps of: integrating said input signal in a first sense to provide an integrating signal, simultaneously therewith integrating a reference signal in a second sense opposite said first sense to reduce the amplitude of said integrated signal, periodically comparing the amplitudes of said integrated and reference signals, geometrically adjusting a digital signal according to each comparison, converting each said adjusted digital signal to analog form to provide said reference signal, and totalizing, over a predetermined measuring interval, the values of each said adjusted digital signal at the time of each comparison, thus to provide said output digital signal.
Claim 3
Dependent Claim
58 words
The method of claim 1 wherein said adjusting step increments or decrements a counter in accordance with said difference to provide (a) a geometric procession or recession, respectively, in a D/A converter for the generation of said reference signal and (b) a higher or lower order input to a counter for totalizing to provide said output digital signal.
Claim 4
Dependent Claim
176 words
An analog to digital converter for converting an input analog signal to an output digital signal comprising: an integrator having opposite polarity inputs and an output, a source of a reference signal coupled to one of said integrator inputs, means for coupling said input analog signal to the other of said integrator inputs, a comparator for periodically comparing in amplitude said integrator output with said reference signal, a first counter coupled to said comparator for periodically incrementing in count when said comparison determines that the integrator output exceeds said reference signal and decrementing in count when said comparison determines that the integrator output is less than said reference signal, said reference signal source comprising a digital to analog converter coupled to the output of said counter for geometrically varying the amplitude of said reference signal in accordance with the count in said first counter, and a second counter for counting over a predetermined measuring interval at a geometric rate that varies in accordance with the count in said first counter to provide said output digital signal.
Claim 5
Dependent Claim
176 words
An analog to digital converter for converting an input analog signal to an output digital signal comprising: an integrator having opposite polarity inputs and an output, a source of a reference signal coupled to one of said integrator inputs, means for coupling said input analog signal to the other of said integrator inputs, a comparator for periodically comparing in amplitude said integrator output with said reference signal, a first counter coupled to said comparator for periodically incrementing in count when said comparison determines that the integrator output exceeds said reference signal and decrementing in count when said comparison determines that the integrator output is less than said reference signal, said reference signal source comprising a digital to analog converter coupled to the output of said counter for geometrically varying the amplitude of said reference signal in accordance with the count in said first counter, and a second counter for counting over a predetermined measuring interval at a geometric rate that varies in accordance with the count in said first counter to provide said output digital signal.
Claim 6
Dependent Claim
40 words
The analog to digital converter of claim 3 wherein said converter includes a range decoder coupled to the output of said first counter for providing a reference signal that varies geometrically in accordance with the output of said first counter.
Claim 7
Dependent Claim
21 words
The analog to digital converter of claim 4 wherein said second counter is coupled to the output of said range decoder.
Claim 8
Dependent Claim
18 words
The analog to digital converter of claim 5 wherein said comparator and said second counter are periodically enabled.
Claim 9
Dependent Claim
27 words
The analog to digital converter of claim 6 wherein said comparator and said second counter are enabled a predetermined number of times to provide a measuring interval.
Claim 10
Dependent Claim
36 words
The analog to digital converter of claim 4 which includes a second range decoder coupled to the output of said first counter, said second counter having an input coupled to the output of said range decoder.
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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) | 1984-01-06 | 1984-07-07 | 1985-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-06 | 1988-07-07 | 1989-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-06 | 1992-07-07 | 1993-01-06 | $7700.00 | Window Closed / Lapsed |