US3579219A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Leakage-current detector
Assignee: Sola Basic Industries Inc
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Filing: 1968-11-19
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Granted: 1971-05-18
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Expires: 1988-11-19
Abstract
Abstract A leakage current or fault detector for isolated power lines in which independent detection circuits each including identical R-C networks operate sequentially from each line to ground. Any fault is fed into a magnetic summing amplifier which is of the failsafe type and drives an indicating relay. The fault may be either capacitive or resistive, or both, and is detected on either or both lines, including a symmetrical fault. The detection circuits may be sequentially sampled by electronically operated photosensitive devices.
Inventors
- 👤 Bodo M Wolfframm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:34
CPC Classifications
G; G08; G08B; G08B21/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
100 words
A leakage current detector for isolated power lines which comprises a plurality of independent detection circuit means, one for each of said power lines, switching means for sequentially connecting each of said circuit means to ground-connecting means thereby sequentially to sample each of the detection circuits, a relay means for operating a fault-indicating signal, circuit means including a bistable means for operating said relay means, said bistable means comprising a magnetic amplifier having sufficient positive feedback to provide bistable operation from the output of the magnetic amplifier, and control means for triggering said bistable means connected in said groundconnecting means.
Claim 2
Dependent Claim
100 words
A leakage current detector for isolated power lines which comprises a plurality of independent detection circuit means, one for each of said power lines, switching means for sequentially connecting each of said circuit means to ground-connecting means thereby sequentially to sample each of the detection circuits, a relay means for operating a fault-indicating signal, circuit means including a bistable means for operating said relay means, said bistable means comprising a magnetic amplifier having sufficient positive feedback to provide bistable operation from the output of the magnetic amplifier, and control means for triggering said bistable means connected in said groundconnecting means.
Claim 3
Dependent Claim
47 words
A leakage detector as defined in claim 1 in which said bistable means provides for energization of said relay means during periods of no leakage fault and deenergization of the relay means upon occurrence of a fault, thereby to provide a fail-safe operation of said relay means.
Claim 4
Dependent Claim
41 words
A leakage detector as defined in claim 2 in which said relay means includes a contact connected to a nonfault indicator circuit means upon energization of the relay and a contact for operating said fault-indicating signal upon deenergization of said relay.
Claim 5
Dependent Claim
20 words
A leakage detector as defined in claim 3 in which said fault-indicating signal comprises a lamp and an audible signal.
Claim 6
Dependent Claim
27 words
A leakage detector as defined in claim 1 in which r3ctifying bridge means control the flow of current through said control means and said ground connecting means.
Claim 7
Dependent Claim
32 words
A leakage detector as defined in claim 1 in which variable resistor means connected between said detection circuit means and said ground connecting means provides for balancing said independent detection circuit means.
Claim 8
Dependent Claim
29 words
A leakage detector as defined in claim 1 in which circuit means including coil means on said amplifier and a variable resistance provide trip-point control for said magnetic amplifier.
Claim 9
Dependent Claim
41 words
A leakage detector as defined in claim 1 in which said switching means comprises a plurality of photosensitive devices, one for each of said detection circuit means, and means including sequentially operated lamps provide for effecting conduction of said photosensitive devices.
Claim 10
Dependent Claim
27 words
A leakage detector as defined in claim 8 in which said lamps are of the neon type and comprise operative elements of a free-running multivibrator circuitry means.
Claim 11
Dependent Claim
42 words
A leakage detector as defined in claim 1 in which a rectifying bridge circuit is connected in each of said detection circuit means, one part of said bridge circuit being connected to said switching means and another part to said ground-connecting means.
Claim 12
Dependent Claim
27 words
A leakage detector as dEfined in claim 1 in which a rectifying bridge is connected in said ground-connecting means between said switching means and said control means.
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) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |