Patent US3246228A successfully refreshed from Google Patents.
US3246228A
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Static frequency changer
Assignee: Emerson Electric Co
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Filing: 1961-12-04
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Granted: 1966-04-12
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Expires: 1981-12-04
Abstract
No abstract record available.
Inventors
- 👤 Cornelis B A Wickenhagen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:19
CPC Classifications
H; H02; H02M; H02M5/00; H02M5/02; H02M5/04; H02M5/22; H02M5/25; H02M5/27; H02M5/271; H02M5/005
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
118 words
IN AN ALTERNATING CURRENT SYSTEM FOR SUPPLYING ELECTRICAL ENERGY AT A SELECTED FREQUENCY FROM A THREE-PHASE SUPPLY LINE INDEPENDENTLY OF THE LINE FREQUENCY; A LOAD COUPLING TRANSFORMER HAVING THREE PRIMARY WINDINGS AND A SECONDARY WINDING INDUCTIVELY COUPLED TO EACH OF SAID PRIMARY WINDINGS; A CIRCUIT FOR EACH PRIMARY WINDING CONNECTING THE PRIMARY WINDING ACROSS ONE PHASE OF THE SOURCE, EACH CIRCUIT INCLUDING, IN SERIES, FIRST AND SECOND CONTROLLED RECTIFIERS ARRANGED IN OPPOSING POLARITIES, AND BY-PASSING UNIDIRECTIONALLY CONDUCTIVE DEVICE PARALLELING THE CONTROLLED RECTIFIERS AND ARRANGED TO PASS CURRENT IN DIRECTIONS OPPOSITE THAT OF THEIR CORRESPONDING CONTROLLED RECTIFIERS; AND COMMON SIGNAL MEANS FOR TRIGGERING THE FIRST CONTROLLED RECTIFIERS AND THE SECOND CONTROLLED RECTIFIERS IN 180* RELATIONSHIP AT A SELECTED FREQUENCY.
Claim 2
Dependent Claim
118 words
IN AN ALTERNATING CURRENT SYSTEM FOR SUPPLYING ELECTRICAL ENERGY AT A SELECTED FREQUENCY FROM A THREE-PHASE SUPPLY LINE INDEPENDENTLY OF THE LINE FREQUENCY; A LOAD COUPLING TRANSFORMER HAVING THREE PRIMARY WINDINGS AND A SECONDARY WINDING INDUCTIVELY COUPLED TO EACH OF SAID PRIMARY WINDINGS; A CIRCUIT FOR EACH PRIMARY WINDING CONNECTING THE PRIMARY WINDING ACROSS ONE PHASE OF THE SOURCE, EACH CIRCUIT INCLUDING, IN SERIES, FIRST AND SECOND CONTROLLED RECTIFIERS ARRANGED IN OPPOSING POLARITIES, AND BY-PASSING UNIDIRECTIONALLY CONDUCTIVE DEVICE PARALLELING THE CONTROLLED RECTIFIERS AND ARRANGED TO PASS CURRENT IN DIRECTIONS OPPOSITE THAT OF THEIR CORRESPONDING CONTROLLED RECTIFIERS; AND COMMON SIGNAL MEANS FOR TRIGGERING THE FIRST CONTROLLED RECTIFIERS AND THE SECOND CONTROLLED RECTIFIERS IN 180* RELATIONSHIP AT A SELECTED FREQUENCY.
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) | 1969-04-11 | 1969-10-11 | 1970-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-04-11 | 1973-10-11 | 1974-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-04-11 | 1977-10-11 | 1978-04-12 | $7700.00 | Window Closed / Lapsed |