Patent US3614532A successfully refreshed from Google Patents.
US3614532A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Triggered vacuum gap keep-alive circuit
Assignee: General Electric Co
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Filing: 1970-06-01
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Granted: 1971-10-19
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Expires: 1990-06-01
Abstract
Abstract This disclosure relates to a ''''keep-alive'''' circuit for a triggered vacuum gap wherein the duration of the usual trigger pulse is insufficiently long to maintain the vacuum gap in an active state for more than one-half cycle at the powerline frequency. A circuit utilizing current transformers is described wherein a current transformer provides the trigger pulse necessary to maintain the vacuum gap in an active state for as long as necessary to protect electrical equipment shunted by the vacuum gap.
Inventors
- 👤 Sidney R Smith Jr
- 👤 Willem F Westendorp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:26
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/02; H02H3/021; H02H3/023; H02H7/00; H02H7/16
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
145 words
An overcurrent protection circuit comprising: current transformer means having a primary and secondary winding, said primary winding connected in series with a device to be protected, triggered vacuum gap means having a pair of main electrodes and a trigger means for activating said triggered vacuum gap by interacting with one of said main electrodes, pilot gap means having a first and second electrode, said pilot gap means having its first electrode connected to said secondary winding and said trigger means and its second electrode coupled to the other of said main electrodes, whereby an overcurrent through the device to be protected induces a trigger voltage in the secondary of said current transformer means causing an electric discharge across said pilot gap which, in turn, causes the trigger means to activate said triggered vacuum gap means thereby shunting the current around the devIce to be protected.
Claim 2
Dependent Claim
145 words
An overcurrent protection circuit comprising: current transformer means having a primary and secondary winding, said primary winding connected in series with a device to be protected, triggered vacuum gap means having a pair of main electrodes and a trigger means for activating said triggered vacuum gap by interacting with one of said main electrodes, pilot gap means having a first and second electrode, said pilot gap means having its first electrode connected to said secondary winding and said trigger means and its second electrode coupled to the other of said main electrodes, whereby an overcurrent through the device to be protected induces a trigger voltage in the secondary of said current transformer means causing an electric discharge across said pilot gap which, in turn, causes the trigger means to activate said triggered vacuum gap means thereby shunting the current around the devIce to be protected.
Claim 3
Dependent Claim
98 words
An overcurrent protective circuit as set forth in claim 1 wherein: said current transformer means comprises first and second current transformers, each having a primary and a secondary winding and each having its primary winding connected in series with the device to be protected, said triggered vacuum gap means comprises a pair of main electrodes, a pair of trigger electrodes, said trigger electrodes located one each in close proximity to each of the main electrodes so as to induce, when activated, an electric discharge between said main electrodes, and said pilot gap is connected to said trigger electrodes.
Claim 4
Dependent Claim
21 words
An overcurrent protection circuit as set forth in claim 2 further comprising: a current-limiting resistance in series with said pilot gap.
Claim 5
Dependent Claim
22 words
An overcurrent protection circuit as set forth in claim 3 further comprising: load means connected across the secondary of each current transformer.
References Cited (Backward Citations)
US3538381A
Cited
US3489873A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-18 | 1975-04-19 | 1975-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-18 | 1979-04-19 | 1979-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-18 | 1983-04-19 | 1983-10-19 | $7700.00 | Window Closed / Lapsed |