Patent US3885213A successfully refreshed from Google Patents.
US3885213A
Expired / Lapsed
US
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Measuring probe for intense and variable electric currents
Assignee: Bpifrance Financement SA
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Filing: 1973-01-09
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Granted: 1975-05-20
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Expires: 1993-01-09
Abstract
Abstract The probe comprises a metallic wire formed into a core on itself or on an insulating coil and arranged so as to form a plurality of turns of the same cross section and distributed regularly along an axis. The coil is adapted to surround the conductor traversed by the variable current to be measured so that this current induces a measuring signal in said turns. The metallic wire is resistant to electric current being made, e.g., of at least 10% Ni and at least 30% Cr. The circuit of the metallic wire is closed by a resistance and capacitor in series, these components having low value relative to that of the metallic wire. First and second voltmeter means are provided at the terminals of the resistance and the capacitor respectively.
Inventors
- 👤 Francoise Rioux
- 👤 Christian Rioux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:40
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/18; G01R15/181
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
144 words
Probe for measuring intense and variable electric currents in a conductor, said probe comprising a metallic wire coil having an insulating core and being arranged so as to form a plurality of turns of the same cross-section which are distributed regularly along an axis adapted to surround the conductor traversed by the variable current to be measured so that the variable current induces a measuring signal in said turns, said metallic wire coil comprising first and second end terminals, and a measuring impedance being directly arranged between said terminals, said measuring impedance comprises a resistor and a capacitor connected in series, a first volt meter means being connected across said resistor and a second volt meter means being connected across said capacitor, the value of the resistance of said metallic wire being at least ten times greater than the value of said measuring impedance.
Claim 2
Dependent Claim
144 words
Probe for measuring intense and variable electric currents in a conductor, said probe comprising a metallic wire coil having an insulating core and being arranged so as to form a plurality of turns of the same cross-section which are distributed regularly along an axis adapted to surround the conductor traversed by the variable current to be measured so that the variable current induces a measuring signal in said turns, said metallic wire coil comprising first and second end terminals, and a measuring impedance being directly arranged between said terminals, said measuring impedance comprises a resistor and a capacitor connected in series, a first volt meter means being connected across said resistor and a second volt meter means being connected across said capacitor, the value of the resistance of said metallic wire being at least ten times greater than the value of said measuring impedance.
Claim 3
Dependent Claim
14 words
Probe as claimed in claim 1 wherein said insulating core comprises an air core.
Claim 4
Dependent Claim
20 words
Probe according to claim 1, wherein said resistivity of said coil is at least equal to 50 Mu Omega -cm.
Claim 5
Dependent Claim
27 words
Probe according to claim 3, wherein said wire comprises an alloy of nickel and of chromium comprising at least 10 and at the most 30% of chromium.
Claim 6
Dependent Claim
14 words
Probe according to claim 1, wherein the cross-section of the metallic wire is slight.
Claim 7
Dependent Claim
59 words
Probe according to claim 1, wherein said coil is in the form of a torus and wherein the resistivity Rho of said wire expressed in Omega -m, the radius of said axis of saId coil expressed in meters and the cross-section s of the wire of the probe expressed in m2 obey the following relationship: Rho R1/s about 10.
Claim 8
Dependent Claim
27 words
Probe according to claim 1, wherein the coefficient of variation of resistivity of the constituent material of the metallic wire as a function of temperature is low.
Claim 9
Dependent Claim
80 words
Probe according to claim 1, wherein said resistance and this capacitor have, respectively, a low value and a low impedance relative to the value of the resistance of said metallic wire, the first voltmeter means being adapted to give a representative indication of the variation as a function of time of the intensity of the current to be measured and the second voltmeter means being adapted to give a representative indication of the intensity of said current to be measured.
Claim 10
Dependent Claim
74 words
Probe according to claim 8, wherein a measuring inductance is installed in series with said measuring resistance, the first voltmeter means being installed at the terminals of said resistance and of said inductance in series and the values Lm and Rm of this inductance and of this resistance satifying the following relationship. Lm/Rm L/R L and R being respectively the values of the inductance and of the resistance of the wire of the probe.
Claim 11
Dependent Claim
47 words
Probe according to claim 8, wherein the capacity of the measuring capacitor is selected so that the product of this capacity and the value of the resistance of said metallic wire is large with respect to the duration of each pulse of the current to be measured.
Claim 12
Dependent Claim
47 words
Probe according to claim 1, comprising a return wire from the last turn of the coil to the first turn of the coil, said return wire being arranged inside the turns and having a low electrical resistance with respect to that of the wire constituting the turns.
Claim 13
Dependent Claim
95 words
Probe according to claim 1, comprising a cap constituted of a good conductor metal traversed by an opening intended for the passage of the conductor traversed by the current to be measured and pierced by a cavity comprising a first portion adapted to receive the metallic wire adapted to surround said conductor and a second portion extending the first portion and of smaller width, this second portion ending at the outer surface of said cap being arranged to allow the magnetic field created by the current to be measured, to penetrate into the first portion.
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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |