US4243936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for magneto-optical current measurements
Assignee: Siemens AG
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Filing: 1978-12-18
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Granted: 1981-01-06
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Expires: 1998-12-18
Abstract
Abstract A method is described for magneto-optical current measurements using a linearly polarized light beam in which the light beam is alternatingly polarized by polarization modulation at a given frequency in two orthogonal directions and the intensities of two signals corresponding to the two states of polarization are picked up sequentially at the frequency of the modulating signal and are processed simultaneously, eliminating the noise component of the measurement signal. The method is particularly useful for the measurement of currents in high voltage systems.
Inventors
- 👤 Alfred Papp
- 👤 Hauke Harms
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:37
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/24; G01R15/245; G01R15/246
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
116 words
In a method for the magneto-optical measurement of currents which includes the step of rotating the plane of polarization of a linearly polarized light beam in dependence on the current to be measured, there being a modulation signal superimposed on the measurement signal, the improvement comprising the steps of: switching the light beam in alternation, by polarization modulation at the frequency of the modulation signal, to each of two orthogonal directions of polarization, detecting, and the intensity signal associated with each direction of polarization and sequentially directing the resulting signals into separate electronic channels at the frequency of the modulation signal, and combining the separate electronic signals to eliminate the noise component of the measurement signal.
Claim 2
Dependent Claim
116 words
In a method for the magneto-optical measurement of currents which includes the step of rotating the plane of polarization of a linearly polarized light beam in dependence on the current to be measured, there being a modulation signal superimposed on the measurement signal, the improvement comprising the steps of: switching the light beam in alternation, by polarization modulation at the frequency of the modulation signal, to each of two orthogonal directions of polarization, detecting, and the intensity signal associated with each direction of polarization and sequentially directing the resulting signals into separate electronic channels at the frequency of the modulation signal, and combining the separate electronic signals to eliminate the noise component of the measurement signal.
Claim 3
Dependent Claim
38 words
The method of claim 1, in which the electronic signals are combined by storing one signal and forming, with it and the other sequential intensity signal, the quotient of the difference and the sum of the intensity signals.
References Cited (Backward Citations)
US2877308A
Cited
US3629703A
Cited
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 |