Patent US3293497A successfully refreshed from Google Patents.
US3293497A
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Ground fault detector
Assignee: Individual
•
Filing: 1962-04-03
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Granted: 1966-12-20
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Expires: 1982-04-03
Abstract
No abstract record available.
Inventors
- 👤 Abraham B Brandler
- 👤 William C Broderick
- 👤 Szalkay John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:26
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/26; H02H3/32; H02H3/34; H02H3/353
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
116 words
A GROUND FAULT DETECTOR FOR POLYPHASE TRANSMISSION SYSTEMS HAVING A CONDUCTOR FOR EACH PHASE AND A CONDUCTOR FOR A SYSTEMS GROUND COMPRISING: (A) AN IMPEDANCE COMPONENT CONNECTED BETWEEN EACH OF SAID CONDUCTORS AND A REFERENCE JUNCTION TERMINAL, (B) COUPLING MEANS ASSOCIATED WITH SAID IMPEDANCE COMPONENTS FOR OBTAINING A VOLTAGE WHICH IS PROPORTIONAL TO THE VECTOR SUM OF THE VOLTAGES BETWEEN SAID CONDUCTORS AND THE REFERENCE JUNCTION TERMINALS, (C) A COMMON IMPEDANCE COMPONENT CONNECTED BETWEEN SAID JUNCTION TERMINAL AND GROUND FOR THE PASSAGE OF THIRD HARMONIC FREQUENCIES, (D) COUPLING MEANS ASSOCIATED WITH SAID COMMON IMPEDANCE FOR SUBSTRACTING THE THIRD HARMONIC VOLTAGE VALUES FORSAID VECTOR SUM, AND (E) MEANS FOR APPLYING SAID VOLTAGES TO AN ELECTRICAL UTILIZATION DEVICE.
Claim 2
Dependent Claim
116 words
A GROUND FAULT DETECTOR FOR POLYPHASE TRANSMISSION SYSTEMS HAVING A CONDUCTOR FOR EACH PHASE AND A CONDUCTOR FOR A SYSTEMS GROUND COMPRISING: (A) AN IMPEDANCE COMPONENT CONNECTED BETWEEN EACH OF SAID CONDUCTORS AND A REFERENCE JUNCTION TERMINAL, (B) COUPLING MEANS ASSOCIATED WITH SAID IMPEDANCE COMPONENTS FOR OBTAINING A VOLTAGE WHICH IS PROPORTIONAL TO THE VECTOR SUM OF THE VOLTAGES BETWEEN SAID CONDUCTORS AND THE REFERENCE JUNCTION TERMINALS, (C) A COMMON IMPEDANCE COMPONENT CONNECTED BETWEEN SAID JUNCTION TERMINAL AND GROUND FOR THE PASSAGE OF THIRD HARMONIC FREQUENCIES, (D) COUPLING MEANS ASSOCIATED WITH SAID COMMON IMPEDANCE FOR SUBSTRACTING THE THIRD HARMONIC VOLTAGE VALUES FORSAID VECTOR SUM, AND (E) MEANS FOR APPLYING SAID VOLTAGES TO AN ELECTRICAL UTILIZATION DEVICE.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-12-19 | 1970-06-20 | 1970-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-12-19 | 1974-06-20 | 1974-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-12-19 | 1978-06-20 | 1978-12-20 | $7700.00 | Window Closed / Lapsed |