US3693085A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for calibrated high level current measurement using a magnetic field responsive transistor
Assignee: Motors Liquidation Co
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Filing: 1971-07-15
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Granted: 1972-09-19
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Expires: 1991-07-15
Abstract
Abstract A transistor having terminal characteristics dependent on the magnetic field incident on the transistor is used in a current sensing arrangement to measure the level of current in a conductor. A differential output voltage is provided by the transistor proportionate to the magnetic field created by the current in the conductor. Calibration of the current sensor is effected by intensifying or shunting the magnetic field to permit measurement of low and high current levels respectively. The field incident on the transistor is intensified by use of magnetic material to direct the magnetic flux on the transistor to sense low current levels. High current levels are sensed by shunting the magnetic field in a calibrated fashion such that the field impinging on the transistor is maintained within the operational limits of the device; magnetic material is interposed between the transistor and the conductor to afford the requisite shunt path.
Inventors
- 👤 Jack H Beard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:54
CPC Classifications
G; G01; G01R; G01R15/00; G01R15/14; G01R15/146; G01R15/148
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
182 words
A system for sensing the level of current carried by an electrical conductor, comprising: a magnetic responsive transistor disposed in proximity with said electrical conductor, said transistor and said conductor disposed such that the magnetic field circulating about said conductor impinges on said transistor, said transistor being operative to provide a differential output voltage signal wherein the amplitude of the voltage differential is proportional to the intensity of the magnetic field incident on said transistor; a quantity of magnetic material interposed between said transistor and said conductor to partially shield said transistor from the magnetic field circulating about said conductor to provide a calibrated magnetic field at said transistor, said magnetic material providing a shunt path for flux circulating about said conductor such that the flux incident on said transistor is a calibrated, attenuated version of the flux which would be incident on said transistor located in the same relationship to said conductor but without the interposed magnetic material; and a calibrated processing electrical circuit to convert said differential output voltage to an indication of the current level carried by said conductor.
Claim 2
Independent Claim
182 words
A system for sensing the level of current carried by an electrical conductor, comprising: a magnetic responsive transistor disposed in proximity with said electrical conductor, said transistor and said conductor disposed such that the magnetic field circulating about said conductor impinges on said transistor, said transistor being operative to provide a differential output voltage signal wherein the amplitude of the voltage differential is proportional to the intensity of the magnetic field incident on said transistor; a quantity of magnetic material interposed between said transistor and said conductor to partially shield said transistor from the magnetic field circulating about said conductor to provide a calibrated magnetic field at said transistor, said magnetic material providing a shunt path for flux circulating about said conductor such that the flux incident on said transistor is a calibrated, attenuated version of the flux which would be incident on said transistor located in the same relationship to said conductor but without the interposed magnetic material; and a calibrated processing electrical circuit to convert said differential output voltage to an indication of the current level carried by said conductor.
Claim 3
Independent Claim
184 words
A system for sensing the level of current carried by an electrical conductor, comprising: a magnetic responsive transistor disposed in proximity with said electrical conductor, said transistor and said conductor disposed such that the magnetic field circulating about said conductor impinges on said transistor, said transistor being operative to provide a differential output voltage signal wherein the amplitude of the voltage differential is proportional to the intensity of the magnetic field incident on said transistor; a substantially semicylindrical shell of magnetic material interposed between said transistor and said conductor to partially shield said transistor from the magnetic field circulating about said conductor to provide a calibrated magnetic field at said transistor, said magnetic material providing a shunt path for flux circulating about said conductor such that the flux incident on said transistor is a calibrated, attenuated version of the flux which would be incident on said transistor located in the same relationship to said conductor but without the interposed magnetic material; and a calibrated processing electrical circuit to convert said differential output voltage to an indication of the current level carried by said conductor.
Claim 4
Independent Claim
184 words
A system for sensing the level of current carried by an electrical conductor, comprising: a magnetic responsive transistor disposed in proximity with said electrical conductor, said transistor and said conductor disposed such that the magnetic field circulating about said conductor impinges on said transistor, said transistor being operative to provide a differential output voltage signal wherein the amplitude of the voltage differential is proportional to the intensity of the magnetic field incident on said transistor; a substantially semicylindrical shell of magnetic material interposed between said transistor and said conductor to partially shield said transistor from the magnetic field circulating about said conductor to provide a calibrated magnetic field at said transistor, said magnetic material providing a shunt path for flux circulating about said conductor such that the flux incident on said transistor is a calibrated, attenuated version of the flux which would be incident on said transistor located in the same relationship to said conductor but without the interposed magnetic material; and a calibrated processing electrical circuit to convert said differential output voltage to an indication of the current level carried by said 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) | 1975-09-19 | 1976-03-20 | 1976-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-19 | 1980-03-20 | 1980-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-19 | 1984-03-20 | 1984-09-19 | $7700.00 | Window Closed / Lapsed |