US3778619A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Input connections for differential amplifiers
Assignee: Compteurs Schlumberger SA
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Filing: 1972-03-22
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Granted: 1973-12-11
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Expires: 1992-03-22
Abstract
Abstract Two polarized light beams from the same source are rotated by passage through Faraday rods having windings supplied by a current to be measured. The beams are then counterrotated by passage through second Faraday rods having windings supplied by a compensating current. Each beam is then applied to a beam splitting semi-reflective mirror which displaces it into distinguishable components. Optical analyzers then attenuate each beam in accordance with a function of the angular displacement from reference or preferential polarization planes. Pairs of photoresponsive detectors transduce the resulting beams into pairs of electrical signals, each pair having a signal of different sign or sense. Signals of like sign are then combined and the two resulting signals are applied to the two inputs of a differential amplifier. The amplifier output is used to develop a proportional compensation signal for the second Faraday rods and can be displayed as a measure of input current.
Inventors
- 👤 A Carnel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:38
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/10; G01R15/00; G01R15/14; G01R15/24; G01R15/247; G02; G02F; G02F1/00; G02F1/01; G02F1/09; G02F1/092
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
168 words
An apparatus for the differential processing of radiant energy signals received by photodetectors from a light source, the source being of the type which emits beams over two different paths, each beam having an identifiable characteristic affected by an input signal whereby fortuitous influences on the paths are eliminated, the apparatus comprising: beam splitting means in each of the paths for splitting each beam into two components, each component having identifiable characteristics; a pair of photodetectors associated with each of said beam splitting means for separately detecting said two components and for producing electrical signals representative thereof; optical analyzer means disposed in the beam path between each of said photodetectors and its associated beam splitting means for attenuating said beam as a predetermined function of its identifiable characteristic; a differential amplifier having two inputs; and means connecting one input of said amplifier to receive the electrical signals produced by one photodetector of each pair, and the other input to receive the electrical signals produced by the remaining photodetectors.
Claim 2
Independent Claim
168 words
An apparatus for the differential processing of radiant energy signals received by photodetectors from a light source, the source being of the type which emits beams over two different paths, each beam having an identifiable characteristic affected by an input signal whereby fortuitous influences on the paths are eliminated, the apparatus comprising: beam splitting means in each of the paths for splitting each beam into two components, each component having identifiable characteristics; a pair of photodetectors associated with each of said beam splitting means for separately detecting said two components and for producing electrical signals representative thereof; optical analyzer means disposed in the beam path between each of said photodetectors and its associated beam splitting means for attenuating said beam as a predetermined function of its identifiable characteristic; a differential amplifier having two inputs; and means connecting one input of said amplifier to receive the electrical signals produced by one photodetector of each pair, and the other input to receive the electrical signals produced by the remaining photodetectors.
Claim 3
Dependent Claim
33 words
An apparatus according to claim 1, wherein each two photodetectorS which produce the signals connected to the same input of the differential amplifier are electrically connected in series circuit relationship with each other.
Claim 4
Dependent Claim
33 words
An apparatus according to claim 1 wherein each two photodetectors which produce the signals connected to the same input of the differential amplifier are electrically connected in parallel circuit relationship with each other.
Claim 5
Dependent Claim
117 words
Appparatus comprising first and second polarized light beams having planes of polarization at angles representative of a variable to be measured; means for separating each of said light beams into a pair of components which are angularly displaced from each other; a differential amplifier; means for receiving each component of said pairs of components and for producing electrical signals representative thereof; and means for combining and providing to one input of said amplifier from each of said pairs of components a signal representative of a component which was angularly displaced in a first direction, and for combining and providing to the other input of said amplifier signals representative of the remaining ones from said pairs of components.
Claim 6
Dependent Claim
117 words
Appparatus comprising first and second polarized light beams having planes of polarization at angles representative of a variable to be measured; means for separating each of said light beams into a pair of components which are angularly displaced from each other; a differential amplifier; means for receiving each component of said pairs of components and for producing electrical signals representative thereof; and means for combining and providing to one input of said amplifier from each of said pairs of components a signal representative of a component which was angularly displaced in a first direction, and for combining and providing to the other input of said amplifier signals representative of the remaining ones from said pairs of components.
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) | 1976-12-10 | 1977-06-11 | 1977-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-10 | 1981-06-11 | 1981-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-10 | 1985-06-11 | 1985-12-11 | $7700.00 | Window Closed / Lapsed |