US3720872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power transmission fault indicator with automatic reset means
Assignee: TAFT ELECTROSYST Inc
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Filing: 1970-09-04
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Granted: 1973-03-13
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Expires: 1990-09-04
Abstract
Abstract A fault indicator is provided which, in the event of normal power line operation, maintains itself in a status that reflects this normal condition. A surge or abnormal increase in the transmitted current reverses the direction of the current flow in at least a part of fault indicator circuit and causes the indicator to reflect the abnormal condition until the restoration of normal line conditions returns the current flow within the fault indicator circuit to its original direction to reestablish a normal condition indication.
Inventors
- 👤 T Russell
- 👤 J Gracie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:59
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/145; G01R19/15; G01R31/00; G01R31/08
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
304 words
Apparatus for indicating the occurrence of current flow through a conductor below a predetermined level, and also for indicating occurrence of current flow through a conductor above said predetermined level, comprising: means including a magnet displaceable between a first indicating position and a second indicating position, said first indicating position for indicating said current flow below said predetermined level and said second indicating position for indicating said current flow above said predetermined level; coil means for establishing a first magnetic field for acting on said magnet and for displacing said magnet to said first indicating position in response to current flow through said coil means in one direction, and for establishing a second magnetic field for acting on said magnet and for displacing said magnet to said second indicating position in response to greater current flow through said coil means in the opposite direction; winding means adapted to be coupled to said conductor and for having a voltage induced therein which is proportional to the current flow in said conductor; means, including serially interconnected diode and resistance means, connected to said coil means and said winding means and for providing a current flow path through said coil means for said current flow through said coil means in said one direction; means, including a voltage sensitive switch having conducting and non-conducting states, connected to said winding means and said coil means, and upon said voltage sensitive switch being in said conducting state for providing a current path, including said voltage sensitive switch, for said greater current through said coil means in said opposite direction; and voltage responsive control means connected to said winding means and said voltage sensitive switch and for placing said voltage sensitive switch in said conducting state upon said current flow in said conductor going from below to above said predetermined level.
Claim 2
Dependent Claim
304 words
Apparatus for indicating the occurrence of current flow through a conductor below a predetermined level, and also for indicating occurrence of current flow through a conductor above said predetermined level, comprising: means including a magnet displaceable between a first indicating position and a second indicating position, said first indicating position for indicating said current flow below said predetermined level and said second indicating position for indicating said current flow above said predetermined level; coil means for establishing a first magnetic field for acting on said magnet and for displacing said magnet to said first indicating position in response to current flow through said coil means in one direction, and for establishing a second magnetic field for acting on said magnet and for displacing said magnet to said second indicating position in response to greater current flow through said coil means in the opposite direction; winding means adapted to be coupled to said conductor and for having a voltage induced therein which is proportional to the current flow in said conductor; means, including serially interconnected diode and resistance means, connected to said coil means and said winding means and for providing a current flow path through said coil means for said current flow through said coil means in said one direction; means, including a voltage sensitive switch having conducting and non-conducting states, connected to said winding means and said coil means, and upon said voltage sensitive switch being in said conducting state for providing a current path, including said voltage sensitive switch, for said greater current through said coil means in said opposite direction; and voltage responsive control means connected to said winding means and said voltage sensitive switch and for placing said voltage sensitive switch in said conducting state upon said current flow in said conductor going from below to above said predetermined level.
Claim 3
Dependent Claim
304 words
Apparatus for indicating the occurrence of current flow through a conductor below a predetermined level, and also for indicating occurrence of current flow through a conductor above said predetermined level, comprising: means including a magnet displaceable between a first indicating position and a second indicating position, said first indicating position for indicating said current flow below said predetermined level and said second indicating position for indicating said current flow above said predetermined level; coil means for establishing a first magnetic field for acting on said magnet and for displacing said magnet to said first indicating position in response to current flow through said coil means in one direction, and for establishing a second magnetic field for acting on said magnet and for displacing said magnet to said second indicating position in response to greater current flow through said coil means in the opposite direction; winding means adapted to be coupled to said conductor and for having a voltage induced therein which is proportional to the current flow in said conductor; means, including serially interconnected diode and resistance means, connected to said coil means and said winding means and for providing a current flow path through said coil means for said current flow through said coil means in said one direction; means, including a voltage sensitive switch having conducting and non-conducting states, connected to said winding means and said coil means, and upon said voltage sensitive switch being in said conducting state for providing a current path, including said voltage sensitive switch, for said greater current through said coil means in said opposite direction; and voltage responsive control means connected to said winding means and said voltage sensitive switch and for placing said voltage sensitive switch in said conducting state upon said current flow in said conductor going from below to above said predetermined level.
Claim 4
Dependent Claim
304 words
Apparatus for indicating the occurrence of current flow through a conductor below a predetermined level, and also for indicating occurrence of current flow through a conductor above said predetermined level, comprising: means including a magnet displaceable between a first indicating position and a second indicating position, said first indicating position for indicating said current flow below said predetermined level and said second indicating position for indicating said current flow above said predetermined level; coil means for establishing a first magnetic field for acting on said magnet and for displacing said magnet to said first indicating position in response to current flow through said coil means in one direction, and for establishing a second magnetic field for acting on said magnet and for displacing said magnet to said second indicating position in response to greater current flow through said coil means in the opposite direction; winding means adapted to be coupled to said conductor and for having a voltage induced therein which is proportional to the current flow in said conductor; means, including serially interconnected diode and resistance means, connected to said coil means and said winding means and for providing a current flow path through said coil means for said current flow through said coil means in said one direction; means, including a voltage sensitive switch having conducting and non-conducting states, connected to said winding means and said coil means, and upon said voltage sensitive switch being in said conducting state for providing a current path, including said voltage sensitive switch, for said greater current through said coil means in said opposite direction; and voltage responsive control means connected to said winding means and said voltage sensitive switch and for placing said voltage sensitive switch in said conducting state upon said current flow in said conductor going from below to above said predetermined level.
Claim 5
Dependent Claim
15 words
Apparatus according to claim 1 wherein said voltage sensitive switch is a silicon controlled rectifier.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |