US3753373A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transducer system
Assignee: Bissett Berman Corp
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Filing: 1965-10-22
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Granted: 1973-08-21
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Expires: 1985-10-22
Abstract
Abstract This invention relates to a system for measuring the value of a variable capacitor. The capacitor is included in a circuit with a reference capacitor which is connected in series with the variable capacitor. An operational amplifier having a high gain is connected in series with one of the variable and reference capacitors and is connected in parallel with the other one of the variable and reference capacitors. An input voltage is applied to the one of the variable and reference capacitors and an output voltage is derived from the operational amplifier. The relative values of the output and input voltages indicate the relative values of the variable and reference capacitors.
Inventors
- 👤 N Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:43
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2605; G01K; G01K7/00; G01K7/34; G01L; G01L1/00; G01L1/14; G01L1/142; G01L1/144; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/125
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
In combination, a variable capacitor having first and second plates movable relative to each other in such manner as to vary the capacitance of the variable capacitor, a high-gain amplifier coupled in parallel with the variable capacitor, means for imparting motion whereby the plates of the variable capacitor move relative to each other in response to the change in a parameter to be measured by the variable capacitor, an input power supply coupled to the variable capacitor, and a readout device coupled to the variable capacitor.
Claim 2
Dependent Claim
86 words
In combination, a variable capacitor having first and second plates movable relative to each other in such manner as to vary the capacitance of the variable capacitor, a high-gain amplifier coupled in parallel with the variable capacitor, means for imparting motion whereby the plates of the variable capacitor move relative to each other in response to the change in a parameter to be measured by the variable capacitor, an input power supply coupled to the variable capacitor, and a readout device coupled to the variable capacitor.
Claim 3
Dependent Claim
142 words
In combination, a variable capacitor having first and second plates movable relative to each other in such manner as to vary the capacitance of the variable capacitor, a reference capacitor coulped in series with the variable capacitor, an AC input power supply coupled in series with the variable capacitor and the reference capacitor, a high-gain amplifier coupled in parallel with the variable capacitor, means for applying a fluid, the pressure of which is to be measured, to the plates of the variable capacitor to cause said plates to move relative to each other in response to the change in the pressure to be measured by the variable capacitor, and a readout device so connected as to sense variations in the capacitance of the variable capacitor and calibrated to derive therefrom readings related to the pressure to be measured by the variable capacitor.
Claim 4
Dependent Claim
142 words
In combination, a variable capacitor having first and second plates movable relative to each other in such manner as to vary the capacitance of the variable capacitor, a reference capacitor coulped in series with the variable capacitor, an AC input power supply coupled in series with the variable capacitor and the reference capacitor, a high-gain amplifier coupled in parallel with the variable capacitor, means for applying a fluid, the pressure of which is to be measured, to the plates of the variable capacitor to cause said plates to move relative to each other in response to the change in the pressure to be measured by the variable capacitor, and a readout device so connected as to sense variations in the capacitance of the variable capacitor and calibrated to derive therefrom readings related to the pressure to be measured by the variable capacitor.
Claim 5
Dependent Claim
128 words
In combination, a variable capacitor, a reference capacitor coupled in series with the variable capacitor, electrostatic shielding arranged to surround the variable capacitor and the reference capacitor and connected to shunt stray capacitances therefrom to ground, means for imparting motion whereby the plates of the variable capacitor move relative to each other in response to the change in a parameter to be measured by the variable capacitor, an input power supply coupled in series with the variable capacitor and the reference capacitor, a high-gain amplifier coupled in parallel with the variable capacitor, and a readout device so connected as to sense variations in the capacitance of the variable capacitor and calibrated to derive therefrom readings related to the change in parameter to be measured by the variable capacitor.
Claim 6
Dependent Claim
128 words
In combination, a variable capacitor, a reference capacitor coupled in series with the variable capacitor, electrostatic shielding arranged to surround the variable capacitor and the reference capacitor and connected to shunt stray capacitances therefrom to ground, means for imparting motion whereby the plates of the variable capacitor move relative to each other in response to the change in a parameter to be measured by the variable capacitor, an input power supply coupled in series with the variable capacitor and the reference capacitor, a high-gain amplifier coupled in parallel with the variable capacitor, and a readout device so connected as to sense variations in the capacitance of the variable capacitor and calibrated to derive therefrom readings related to the change in parameter to be measured by the variable capacitor.
Claim 7
Dependent Claim
207 words
In combination for measuring a parameter, a variable capacitor having first and second plates movable relative to each other in such manner as to vary the capacitance of the variable capacitor, said plates being constructed of different materials having different temperature coefficients of expansion and being so mounted relative to one another that the plates of the variable capacitor will move relative to each other in response to the change in the temperature to be measured by the variable capacitor, a reference capacitor coupled in series with the variable capacitor, an AC input power supply coupled in series with the variable capacitor and the reference capacitor to provide an input voltage, a high-gain operational amplifier coupled in parallel with a particular one of the variable and reference capacitors and in series with the other one of the variable and reference capacitors to provide an output voltage, and a digital readout device connected to sense variations in the value of the variable capacitor relative to the value of the reference capacitor and calibrated to derive therefrom readings related to the change in parameter to be mEasured by the variable capacitor in accordance with the relative values of the input voltage and the output voltage from the operational amplifier.
Claim 8
Dependent Claim
207 words
In combination for measuring a parameter, a variable capacitor having first and second plates movable relative to each other in such manner as to vary the capacitance of the variable capacitor, said plates being constructed of different materials having different temperature coefficients of expansion and being so mounted relative to one another that the plates of the variable capacitor will move relative to each other in response to the change in the temperature to be measured by the variable capacitor, a reference capacitor coupled in series with the variable capacitor, an AC input power supply coupled in series with the variable capacitor and the reference capacitor to provide an input voltage, a high-gain operational amplifier coupled in parallel with a particular one of the variable and reference capacitors and in series with the other one of the variable and reference capacitors to provide an output voltage, and a digital readout device connected to sense variations in the value of the variable capacitor relative to the value of the reference capacitor and calibrated to derive therefrom readings related to the change in parameter to be mEasured by the variable capacitor in accordance with the relative values of the input voltage and the output voltage from the operational amplifier.
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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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |