US4866435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital transmitter with variable resolution as a function of speed
Assignee: Rosemount Inc
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Filing: 1987-10-16
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Granted: 1989-09-12
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Expires: 2007-10-16
Abstract
Abstract A digital transmitter with an analog sensor uses an integrating analog-to-digital (A/D) converter to digitize the analog signal from the sensor. The A/D converter produces a digital output which is a continuous, non-rezeroed integrated average of the analog signal, so that the integrated average of the digital output over time does not contain inherent quantization errors. A microcomputer system digitally filters the signal from the A/D converter, and then uses the digitally filtered signal to produce the transmitter output signal. By varying the response time of the digital filter, the response time and resolution of the transmitter can be varied.
Inventors
- 👤 Roger L. Frick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:57
CPC Classifications
G; G08; G08C; G08C19/00; G08C19/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
81 words
A transmitter for providing an output signal as a function of a sensed parameter, the transmitter comprising: sensing means for providing an analog signal which is a function of the sensed parameter; integrating analog-to-digital (A/D) converter means for producing a digital signal which is a quasi-continuous, non-rezeroed integrated average of the analog signal; means for digitally filtering the digital signal to provide a filtered digital signal; and means for providing the output signal as a function of the filtered digital signal.
Claim 2
Dependent Claim
81 words
A transmitter for providing an output signal as a function of a sensed parameter, the transmitter comprising: sensing means for providing an analog signal which is a function of the sensed parameter; integrating analog-to-digital (A/D) converter means for producing a digital signal which is a quasi-continuous, non-rezeroed integrated average of the analog signal; means for digitally filtering the digital signal to provide a filtered digital signal; and means for providing the output signal as a function of the filtered digital signal.
Claim 3
Dependent Claim
19 words
The transmitter of claim 1 wherein the means for digitally filtering performs one-stage digital filtering of the digital signal.
Claim 4
Dependent Claim
19 words
The transmitter of claim 1 wherein the means for digitally filtering performs two-stage digital filtering of the digital signal.
Claim 5
Dependent Claim
35 words
The transmitter of claim 3 wherein one stage has a fixed time constant equivalent to an A/D converter update time of the integrating A/D converter means and the second stage has an adjustable time constant.
Claim 6
Dependent Claim
18 words
The transmitter of claim 1 wherein the means for digitally filtering performs adaptive filtering of the digital signal.
Claim 7
Dependent Claim
15 words
The transmitter of claim 1 wherein the means for digitally filtering comprises a digital computer.
Claim 8
Dependent Claim
17 words
The transmitter of claim 1 wherein the integrating A/D converter means comprises a charge balancing voltage-to-frequency converter.
Claim 9
Dependent Claim
26 words
The transmitter of claim 1 wherein the sensing means comprises a capacitive sensor and wherein the integrating A/D converter means comprises a charge re-balancing capacitance-to-digital converter.
Claim 10
Dependent Claim
15 words
The transmitter of claim 1 wherein the means for digitally filtering the signal is adjustable.
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) | 1992-09-11 | 1993-03-13 | 1993-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-11 | 1997-03-13 | 1997-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-11 | 2001-03-13 | 2001-09-12 | $7700.00 | Window Closed / Lapsed |