US4544983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Overvoltage protection device
Assignee: Nortel Networks Technology Corp
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Filing: 1983-04-28
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Granted: 1985-10-01
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Expires: 2003-04-28
Abstract
Abstract An overvoltage protection device, for protecting communications equipment against hazardous voltages cue to lightning or power surges, comprises a primary protector, for example a gas tube device, and a back-up protector connected in parallel. The back-up protector includes a semiconductor pn junction, and is preferably a pair of diodes back-to-back. The back-up protector has a breakdown voltage slightly higher than that of the primary protector and is arranged to fail short-circuit once it has operated so as to provide an indication that the primary protector failed to operate.
Inventors
- 👤 James E. Anderson
- 👤 Michael J. Coleman
- 👤 Frederick C. Livermore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:31
CPC Classifications
H; H02; H02H; H02H9/00; H02H9/04; H02H9/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
88 words
An overvoltage protection device, for telephone lines and other communications channels, comprising a primary protector and a secondary protector connected in parallel, the primary protector having in normal operation a first breakdown voltage, the secondary protector comprising a semiconductor pn junction having in normal operation a breakdown voltage greater than said first breakdown voltage and a current-carrying capacity significantly less than the current the pn junction would be required to carry once its aforesaid breakage voltage was exceeded, whereby the pn junction will fail short-circuit following its operation.
Claim 2
Dependent Claim
88 words
An overvoltage protection device, for telephone lines and other communications channels, comprising a primary protector and a secondary protector connected in parallel, the primary protector having in normal operation a first breakdown voltage, the secondary protector comprising a semiconductor pn junction having in normal operation a breakdown voltage greater than said first breakdown voltage and a current-carrying capacity significantly less than the current the pn junction would be required to carry once its aforesaid breakage voltage was exceeded, whereby the pn junction will fail short-circuit following its operation.
Claim 3
Dependent Claim
17 words
An overvoltage protection device as defined in claim 9, wherein said primary protector comprises a gas tube.
Claim 4
Dependent Claim
22 words
An overvoltage protection device as defined in claim 9, wherein said secondary protector comprises a pair of semiconductor junctions in back-to-back configuration.
Claim 5
Dependent Claim
18 words
An overvoltage protection device as defined in claim 4, wherein said secondary protector comprises a pair of diodes.
Claim 6
Dependent Claim
41 words
An overvoltage protection device as defined in claim 2, wherein said secondary protector has input terminals connected to the semiconductor material, which is arranged so as to be fused between said terminals by said current when the breakdown voltage is exceeded.
References Cited (Backward Citations)
US2793331A
Cited
US3558830A
Cited
US3934175A
Cited
US3946278A
Cited
US4023071A
Cited
US4327393A
Cited
US4389695A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-30 | 1989-04-01 | 1989-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-30 | 1993-04-01 | 1993-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-30 | 1997-04-01 | 1997-10-01 | $7700.00 | Window Closed / Lapsed |