US3684955A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wideband balanced current probe
Assignee: Lockheed Martin Corp
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Filing: 1970-07-06
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Granted: 1972-08-15
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Expires: 1990-07-06
Abstract
Abstract A wideband balanced current probe utilized for the detection and accurate measurement of very small currents flowing in a wire disposed in an environment involving extremely high electric and magnetic fields. My probe principally comprises a toroidal core having an electrically symmetrical bifilar wound coil disposed thereon and being protected from the high energy environment by a conductive, nonmagnetic shield. This probe provides a pair of symmetrical output signals which may be trimmed to provide even more precise electrical symmetry. The pair of symmetrical output signals is summed in phase and conveyed without contamination from the high energy field through properly balanced and shielded conductors to a relatively remote data recording unit.
Inventors
- 👤 Duane J Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:34
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/18; G01R15/186; H; H01; H01F; H01F38/00; H01F38/20; H01F38/22; H01F38/28; H01F38/30; H01F38/32
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
162 words
A wideband balanced current probe for use in obtaining time varying data in a hostile environment involving high electric and magnetic fields, comprising a coil assembly of generally toroidal configuration disposed in a case forming a shield, said coil assembly comprising a core and a bifilar winding disposed upon said core, said bifilar winding being constituted by a pair of windings in which the impedance of one winding is virtually identical to the impedance in tHe other winding, said case also having an output connector to which the ends of said bifilar winding are connected in a balanced manner, with the interconnection of said windings being such that any signals induced into the pair of windings by a contaminating field will be canceled, whereby when a current carrying conductor is disposed through the open portion of said toroidal coil assembly, the time-varying current flowing through the conductor can be measured, and transferred to an external location without contamination by the high fields.
Claim 2
Dependent Claim
162 words
A wideband balanced current probe for use in obtaining time varying data in a hostile environment involving high electric and magnetic fields, comprising a coil assembly of generally toroidal configuration disposed in a case forming a shield, said coil assembly comprising a core and a bifilar winding disposed upon said core, said bifilar winding being constituted by a pair of windings in which the impedance of one winding is virtually identical to the impedance in tHe other winding, said case also having an output connector to which the ends of said bifilar winding are connected in a balanced manner, with the interconnection of said windings being such that any signals induced into the pair of windings by a contaminating field will be canceled, whereby when a current carrying conductor is disposed through the open portion of said toroidal coil assembly, the time-varying current flowing through the conductor can be measured, and transferred to an external location without contamination by the high fields.
Claim 3
Dependent Claim
70 words
The probe as defined in claim 1 in combination with a data acquisition unit to which said output connector is electrically connected, said electrical connection involving the use of multiple shielded leads, said data acquisition unit involving means for simultaneously utilizing a number of probes, but with switching means being provided such that an output reading can be obtained from a selected probe by suitable operation of said switching means.
Claim 4
Dependent Claim
69 words
The wideband current probe as defined in claim 1 in which said case and said coil assembly are split, with the case being hinged to permit the core portions to be moved apart and thus placed around at least one conductor whose end is not available to be passed through the toroid, and means for holding the case in a closed, toroid-completely position after being placed around the conductor.
Claim 5
Dependent Claim
152 words
A wideband, highly symmetrical balanced probe for use in sensing time varying current flowing in a conductor disposed in a high electric and/or high magnetic field, comprising a coil assembly of toroidal configuration, a case of conductive, nonmagnetic material disposed in surrounding relation about said coil assembly to accomplish the shielding thereof from said fields, said case having an output connector equipped with terminals, said coil assembly comprising a core, and a bifilar winding disposed for a plurality of turns about said core, with one wire of each terminus of said bifilar winding being electrically attached to a respective terminal of said output connector, with the other wire of each terminus being connected to the body of the output connector, whereby when a shielded conductor is attached to the terminals of said connector, the signal generated in said winding can be transferred to a remote location without contamination by the high fields.
Claim 6
Dependent Claim
152 words
A wideband, highly symmetrical balanced probe for use in sensing time varying current flowing in a conductor disposed in a high electric and/or high magnetic field, comprising a coil assembly of toroidal configuration, a case of conductive, nonmagnetic material disposed in surrounding relation about said coil assembly to accomplish the shielding thereof from said fields, said case having an output connector equipped with terminals, said coil assembly comprising a core, and a bifilar winding disposed for a plurality of turns about said core, with one wire of each terminus of said bifilar winding being electrically attached to a respective terminal of said output connector, with the other wire of each terminus being connected to the body of the output connector, whereby when a shielded conductor is attached to the terminals of said connector, the signal generated in said winding can be transferred to a remote location without contamination by the high fields.
Claim 7
Dependent Claim
69 words
The balanced probe as defined in claim 4 in which output leads are attached to said output connector, which leads are connected to sensitive means for acquiring and recording the data derived by the use of said probe, said leads being shielded as they extend between components, said leads and the components used in said acquiring and recording means in connection with the obtaining of data being carefully balanced.
Claim 8
Dependent Claim
74 words
The wideband current probe as defined in claim 4 in which said case and said coil assembly are split, with the case being hinged to permit the portions of the coil assembly to be moved apart and thus placed around at least one conductor whose end is not available to be passed through the toroidal coil assembly, and means for holding the case in a closed, toroid-completing position after being placed around the conductor.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |