US3597683A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current transformer utilizing an electromagnetic wave, a faraday rotator, circular waveguides, horn antennae, and mode converters to measure current in a high voltage transmission line
Assignee: Individual
•
Filing: 1970-04-24
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Granted: 1971-08-03
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Expires: 1990-04-24
Abstract
Abstract A laser beam is directed from a ground potential site to a Faraday rotation element provided in the magnetic field produced by the current in high voltage transmission line. The Faraday rotation element rotates a plane of polarization of the laser beam in accordance with the intensity of the magnetic field. The laser beam is transmitted through the Faraday rotation element to a polarization analyzer at the site. The analyzer produces an output proportional to the magnitude of the current in the line. In another embodiment, waveguide means are used to direct an electromagnetic wave from a ground potential site to a Faraday rotation element in the magnetic field produced by the current in the high voltage transmission line and back to the ground potential site. The wave is transmitted and received along the same path between a pair of horn antennae.
Inventors
- 👤 Shigebumi Saito
- 👤 Yoichi Fujii
- 👤 Yutaka Ohno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:37
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/24; G01R15/245; G01R15/246
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
260 words
A current transformer for measuring apparatus utilizing an electromagnetic wave for measuring the current in a high voltage transmission line, said current transformer comprising: a ground potential site for transmitting to said high voltage transmission line an electromagnetic wave; a Faraday rotation element provided in the magnetic field produced by the current in said high voltage transmission line for modulating an electromagnetic wave transmitted from said site in accordance with the intensity of said magnetic field; electromagnetic wave generating means at said ground potential site for directing the electromagnetic wave from said site to said magnetic effect element; guide means for transmitting the electromagnetic wave, said guide means including a mOde converter, a first circular waveguide at said ground potential site, a first horn antenna at said ground potential site, a second horn antenna at said high voltage transmission line, a second circular waveguide at said high voltage transmission line, said mode converter being coupled to said first circular waveguide for converting the mode of the electromagnetic wave transmitted from said ground potential site to the TE11 mode, each of said first and second horn antennae being mounted at an end of a corresponding one of said circular waveguides facing the other; and receiving means at said ground potential site for receiving the modulated electromagnetic wave, said receiving means including a directional coupler coupled to said first circular waveguide and demodulating means connected to said receiving means for converting the received modulated electromagnetic wave to an output proportional to the magnitude of the current in said high voltage transmission line.
Claim 2
Dependent Claim
260 words
A current transformer for measuring apparatus utilizing an electromagnetic wave for measuring the current in a high voltage transmission line, said current transformer comprising: a ground potential site for transmitting to said high voltage transmission line an electromagnetic wave; a Faraday rotation element provided in the magnetic field produced by the current in said high voltage transmission line for modulating an electromagnetic wave transmitted from said site in accordance with the intensity of said magnetic field; electromagnetic wave generating means at said ground potential site for directing the electromagnetic wave from said site to said magnetic effect element; guide means for transmitting the electromagnetic wave, said guide means including a mOde converter, a first circular waveguide at said ground potential site, a first horn antenna at said ground potential site, a second horn antenna at said high voltage transmission line, a second circular waveguide at said high voltage transmission line, said mode converter being coupled to said first circular waveguide for converting the mode of the electromagnetic wave transmitted from said ground potential site to the TE11 mode, each of said first and second horn antennae being mounted at an end of a corresponding one of said circular waveguides facing the other; and receiving means at said ground potential site for receiving the modulated electromagnetic wave, said receiving means including a directional coupler coupled to said first circular waveguide and demodulating means connected to said receiving means for converting the received modulated electromagnetic wave to an output proportional to the magnitude of the current in said high voltage transmission line.
Claim 3
Dependent Claim
52 words
A current transformer as claimed in claim 1, wherein said directional coupler is so coupled to said first circular waveguide that the plane of polarization of the electromagnetic wave radiated to said circular waveguide from said mode converter forms an angle of 45* with the plane of polarization of said directional coupler.
References Cited (Backward Citations)
US3274516A
Cited
US3212031A
Cited
US3413055A
Cited
US3312895A
Cited
US3363174A
Cited
US3324393A
Cited
US3419802A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |