Patent US3801908A successfully refreshed from Google Patents.
US3801908A
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Current measuring apparatus employing magnetic switch
Assignee: Akzo NV
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Filing: 1972-03-09
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Granted: 1974-04-02
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Expires: 1992-03-09
Abstract
Abstract Current measuring apparatus for determining the strength of the current in an electric conductor. The apparatus comprises an actuating coil, a magnetic switch positioned within the composite magnetic field produced by the currents flowing through the conductor and the actuating coil, generating means coupled to the actuating coil for providing an increasing exciting current or an increasing step-wise voltage thereto, and measuring apparatus coupled to the magnetic switch for determining the instant at which the switch changes from one state to the other under the influence of the composite magnetic field. The current through the actuating coil at the instant that the switch changes states corresponds to the magnitude of the current through the electric conductor. The apparatus may be used in conjunction with the operation of electrolytic cells having large numbers of anodes wherein it is useful to know the current flowing through each anode.
Inventors
- 👤 Andel E Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:00
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/146; G01R15/148
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
142 words
Current measuring apparatus for determining the strength of the current in at least one electric conductor comprising a. at least one actuating coil for producing a magnetic field corresponding to an exciting current therethrough, b. at least one magnetic switch having a pair of switching states positioned within the composite magnetic field produced by the currents flowing through said conductor and said actuating coil respectively, c. generating means coupled To said actuating coil for providing an exciting current thereto which varies with time, and d. measuring apparatus coupled to said magnetic switch for determining the instant at which said switch changes from one state to the other under the influence of the combined magnetic action of the currents in said conductor and said actuating coil, the current in said actuating coil at said instant corresponding to the current through said electric conductor.
Claim 2
Dependent Claim
142 words
Current measuring apparatus for determining the strength of the current in at least one electric conductor comprising a. at least one actuating coil for producing a magnetic field corresponding to an exciting current therethrough, b. at least one magnetic switch having a pair of switching states positioned within the composite magnetic field produced by the currents flowing through said conductor and said actuating coil respectively, c. generating means coupled To said actuating coil for providing an exciting current thereto which varies with time, and d. measuring apparatus coupled to said magnetic switch for determining the instant at which said switch changes from one state to the other under the influence of the combined magnetic action of the currents in said conductor and said actuating coil, the current in said actuating coil at said instant corresponding to the current through said electric conductor.
Claim 3
Dependent Claim
18 words
Current-measuring apparatus according to claim 1 wherein said actuating coil and said magnetic switch comprise a reed relay.
Claim 4
Dependent Claim
15 words
Current-measuring apparatus according to claim 1 wherein said generating means provides an increasing actuating current.
Claim 5
Dependent Claim
153 words
An electric distribution system having a plurality of current conductors for feeding at least one electrolytic cell comprising a. a plurality of actuating coils for producing a magnetic field corresponding to an exciting current therethrough, b. a plurality of magnetic switches, each having a pair of switching states and each positioned within the magnetic field produced by the current flowing through a corresponding conductor and the magnetic field produced by a corresponding actuator coil, c. generating means coupled to said actuating coils for providing exciting currents therein which vary with time, and d. measuring apparatus coupled to each of said magnetic switches for determining the instant at which said switch changes from one state to the other under the influence of the combined magnetic action of the currents in said corresponding conductor and corresponding actuator coil, the current through said actuating coil at said instant corresponding to the current through said electric conductor.
Claim 6
Dependent Claim
153 words
An electric distribution system having a plurality of current conductors for feeding at least one electrolytic cell comprising a. a plurality of actuating coils for producing a magnetic field corresponding to an exciting current therethrough, b. a plurality of magnetic switches, each having a pair of switching states and each positioned within the magnetic field produced by the current flowing through a corresponding conductor and the magnetic field produced by a corresponding actuator coil, c. generating means coupled to said actuating coils for providing exciting currents therein which vary with time, and d. measuring apparatus coupled to each of said magnetic switches for determining the instant at which said switch changes from one state to the other under the influence of the combined magnetic action of the currents in said corresponding conductor and corresponding actuator coil, the current through said actuating coil at said instant corresponding to the current through said electric conductor.
Claim 7
Dependent Claim
16 words
An electric distribution system according to claim 4 wherein said actuating coils are connected in parallel.
Claim 8
Dependent Claim
18 words
An electric distribution system according to claim 5 wherein said generating means provides a voltage which increases stepwise.
Claim 9
Dependent Claim
17 words
An electric distribution system according to claim 6 wherein the magnitude of said voltage steps is variable.
Claim 10
Dependent Claim
31 words
An electric distribution system according to claim 2 wherein said reed relay is mounted adjacent said conductor with its longitudinal axis transverse to the direction of current flow in said conductor.
Claim 11
Independent Claim
131 words
The method of measuring current in a conductor comprising the steps of a. placing a switch responsive to a magnetic field and having a pair of switching states within a first magnetic field produced by the current flowing through said conductor, b. generating a second magnetic field which surrounds said switch, said first and second magnetic fields forming a composite magnetic field, c. increasing the strength of said second magnetic field until said switch changes from one state to the other under the influence of said composite magnetic field, and d. measuring the strength of said second magnetic field at the instant said switch changes from one state to the other, the strength of said second magnetic field at this instant corresponding to the magnitude of the current in said conductor.
Claim 12
Independent Claim
131 words
The method of measuring current in a conductor comprising the steps of a. placing a switch responsive to a magnetic field and having a pair of switching states within a first magnetic field produced by the current flowing through said conductor, b. generating a second magnetic field which surrounds said switch, said first and second magnetic fields forming a composite magnetic field, c. increasing the strength of said second magnetic field until said switch changes from one state to the other under the influence of said composite magnetic field, and d. measuring the strength of said second magnetic field at the instant said switch changes from one state to the other, the strength of said second magnetic field at this instant corresponding to the magnitude of the current in said conductor.
References Cited (Backward Citations)
US3500109A
Cited
US3518544A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |