Patent US2706439A successfully refreshed from Google Patents.
Patent US4392174A successfully refreshed from Google Patents.
US4392174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric protection device
Assignee: Telemecanique SA
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Filing: 1982-06-11
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Granted: 1983-07-05
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Expires: 2002-06-11
Abstract
Abstract A protection device has first and second differential transformers each with a toroidal magnetic core through which pass the neutral and phase conductors of an alternating current distribution network, and a secondary winding. The secondary winding of the first transformer is coupled to the input of an amplifier followed by a rectifier, a threshold comparator and a control device adapted to release a circuit-breaker. The secondary winding of the second transformer is coupled to the output of the amplifier. The improvement is constituted by an auxiliary amplifier inserted between the output of the first amplifier and the terminals of the secondary winding of the second differential transformer.
Inventors
- 👤 Christian Cadet
- 👤 Bernard Dumortier
- 👤 Georges Souques
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:04
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/26; H02H3/32; H02H3/33; H02H3/331
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
130 words
In a protection device comprising first and second differential transformers each having a toroidal magnetic core through which pass the neutral and phase conductors of an alternating current distribution circuit, and a secondary winding, the secondary winding of the first transformer being coupled to the input of a first amplifier followed by a rectifier, a threshold comparator and a control means suitable for actuating a circuit breaker, the secondary winding of the second transformer being coupled to the output of the said first amplifier, the improvement comprising an auxiliary amplifier having an input and an output, the input of the said auxiliary amplifier being coupled to the output of the first amplifier and the output of said auxiliary amplifier being coupled to the secondary winding of the second differential transformer.
Claim 2
Dependent Claim
130 words
In a protection device comprising first and second differential transformers each having a toroidal magnetic core through which pass the neutral and phase conductors of an alternating current distribution circuit, and a secondary winding, the secondary winding of the first transformer being coupled to the input of a first amplifier followed by a rectifier, a threshold comparator and a control means suitable for actuating a circuit breaker, the secondary winding of the second transformer being coupled to the output of the said first amplifier, the improvement comprising an auxiliary amplifier having an input and an output, the input of the said auxiliary amplifier being coupled to the output of the first amplifier and the output of said auxiliary amplifier being coupled to the secondary winding of the second differential transformer.
Claim 3
Dependent Claim
48 words
A protection device, according to claim 1, wherein a first adjustment of gain of the first amplifier determines the sensitivity of the device to differential currents, whilst the auxiliary differential amplifier is provided with a second separate adjustment of gain permitting the adjustment of the conditions of oscillation.
Claim 4
Dependent Claim
20 words
A protection device, according to claim 2, wherein the gain of the first amplifier decreases when its input voltage increases.
Claim 5
Dependent Claim
30 words
A protection device, according to claim 2, wherein the said auxiliary amplifier is arranged to be insensitive to the frequency of the distribution circuit by means of a selective filter.
Claim 6
Dependent Claim
20 words
A protection device, according to claim 4, wherein the gain of the first amplifier decreases when its input voltage increases.
Claim 7
Dependent Claim
20 words
A protection device, according to claim 1, wherein the rectifier is arranged to shape both alternations of the alternating current.
Claim 8
Dependent Claim
20 words
A protection device, according to claim 1, comprising a resistance capacity circuit inserted between the shaper and the threshold comparator.
Claim 9
Dependent Claim
30 words
A protection device, according to claim 1 wherein the said auxiliary amplifier is arranged to be insensitive to the frequency of the distribution circuit by means of a selective filter.
Claim 10
Dependent Claim
20 words
A protection device, according to claim 1 wherein the gain of the first amplifier decreases when its input voltage increases.
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) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |