Patent US3626291A successfully refreshed from Google Patents.
US3626291A
Expired / Lapsed
US
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Current-measuring apparatus
Assignee: Sanwa Business Credit Corp
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Filing: 1969-05-12
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Granted: 1971-12-07
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Expires: 1989-05-12
Abstract
Abstract Apparatus including a set of adjacent coils which form a closed path adapted to be closed about a current-carrying conductor. The voltage output from said coil, which is induced by the closing movement or by changes in the conductor current, is integrated. The integrated value of said voltage being proportional to the current flowing through said conductor.
Inventors
- 👤 Donald W Yauch
- 👤 Paul A Lilie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:40
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/18; G01R15/181; G01R1/00; G01R1/20; G01R1/22
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
186 words
Apparatus for measuring direct current comprising, a housing split into two parts, means for closing said housing about a current-carrying conductor, an air core sensing coil split into two parts, each fixedly mounted in a respective housing part, said coil when said housing is closed, forming a substantially complete toroid around said conductor to permit sampling of the field at all points of a path surrounding said conductor, means including an integrating circuit for detecting the current in the conductor by integrating the current induced in the sensing coil during the period of opening said housing from a closed position encompassing no conductor and thereafter closing the housing about the conductor, leads connecting said integrating circuit to said coil, and an output indicator connected to said integrating circuit, said integrating circuit being characterized in that the permissible rate of closure of said housing about the conductor is independent of the electrical characteristics of the output indicator, whereby substantially identical readings on the output indicator are obtainable irrespective of the rate of closing said housing or of the orientation of said housing with respect to said conductor.
Claim 2
Dependent Claim
186 words
Apparatus for measuring direct current comprising, a housing split into two parts, means for closing said housing about a current-carrying conductor, an air core sensing coil split into two parts, each fixedly mounted in a respective housing part, said coil when said housing is closed, forming a substantially complete toroid around said conductor to permit sampling of the field at all points of a path surrounding said conductor, means including an integrating circuit for detecting the current in the conductor by integrating the current induced in the sensing coil during the period of opening said housing from a closed position encompassing no conductor and thereafter closing the housing about the conductor, leads connecting said integrating circuit to said coil, and an output indicator connected to said integrating circuit, said integrating circuit being characterized in that the permissible rate of closure of said housing about the conductor is independent of the electrical characteristics of the output indicator, whereby substantially identical readings on the output indicator are obtainable irrespective of the rate of closing said housing or of the orientation of said housing with respect to said conductor.
Claim 3
Dependent Claim
37 words
Apparatus according to claim 1 in which said coil comprises, a plurality of coils wound on linear axes, said coils being electrically connected in series, means mounting half said coils end-to-end in each of said housing halves.
Claim 4
Dependent Claim
40 words
Apparatus according to claim 2 further comprising, means for pivotally mounting said housings with respect to each other at one of their ends, a handle supporting said housings, and means mounted on said handle for opening and closing said housings.
Claim 5
Dependent Claim
33 words
Apparatus according to claim 3 wherein each lead from a respective coil half passes through said handle, lies along said coil half and is connected to the free end of said coil half.
Claim 6
Dependent Claim
21 words
Apparatus according to claim 1 in which said integrating circuit comprises an active integrating circuit which derives power from a battery.
Claim 7
Dependent Claim
141 words
Apparatus for measuring direct current comprising, a housing split into two parts, means for closing said housing about a current-carrying conductor, a plurality of air core sensing coils mounted in respective housing parts, said coils being mounted on linear axes and being electrically coNnected in series, some of the coils having a large diameter and the remaining coils having a small diameter, said small coils alternating with said large coils and having their ends inserted in the ends of adjacent large coils, means including an integrating circuit for detecting current in the conductor by integrating the current induced in the sensing coils during the period of opening said housing from a closed position encompassing no conductor and thereafter enclosing the housing about the conductor, leads connecting said integrating circuit to said coils, and an output indicator connected to said integrating circuit.
Claim 8
Dependent Claim
141 words
Apparatus for measuring direct current comprising, a housing split into two parts, means for closing said housing about a current-carrying conductor, a plurality of air core sensing coils mounted in respective housing parts, said coils being mounted on linear axes and being electrically coNnected in series, some of the coils having a large diameter and the remaining coils having a small diameter, said small coils alternating with said large coils and having their ends inserted in the ends of adjacent large coils, means including an integrating circuit for detecting current in the conductor by integrating the current induced in the sensing coils during the period of opening said housing from a closed position encompassing no conductor and thereafter enclosing the housing about the conductor, leads connecting said integrating circuit to said coils, and an output indicator connected to said integrating circuit.
Claim 9
Dependent Claim
31 words
Current-measuring apparatus according to claim 6 in which the axes of at least a portion of said coils lie at an obtuse angle to their adjacent coils to form said toroid.
Claim 10
Dependent Claim
36 words
Apparatus according to claim 6 in which the product of the number of turns per unit length times the area enclosed by a turn of the small coils is equal to that of the large coils.
Claim 11
Independent Claim
109 words
The method of measuring current in a conductor located in a strong magnetic field without the necessity of contacting the conductor using a split sensing coil, an integrator circuit having storage and a meter for reading the value stored on the integrator circuit comprising the steps of, closing said split sensing coil in air to a position in which it encompasses no conductor and discharging any stored signal on the integrator circuit, opening said coil and thereafter closing said coil completely about said conductor, integrating the voltage induced in said coil over the period of closing said coil about said conductor, and indicating the integrated value of said voltage.
Claim 12
Independent Claim
109 words
The method of measuring current in a conductor located in a strong magnetic field without the necessity of contacting the conductor using a split sensing coil, an integrator circuit having storage and a meter for reading the value stored on the integrator circuit comprising the steps of, closing said split sensing coil in air to a position in which it encompasses no conductor and discharging any stored signal on the integrator circuit, opening said coil and thereafter closing said coil completely about said conductor, integrating the voltage induced in said coil over the period of closing said coil about said conductor, and indicating the integrated value of said voltage.
Claim 13
Dependent Claim
20 words
The method according to claim 9 further comprising the preliminary step of closing said coil in air adjacent said conductor.
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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |