Patent US3518525A successfully refreshed from Google Patents.
US3518525A
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US
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System providing a d.c. voltage equal to the r.m.s. value of an unknown a.c. voltage
Assignee: Singer Co
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Filing: 1968-07-19
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Granted: 1970-06-30
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Expires: 1988-07-19
Abstract
No abstract record available.
Inventors
- 👤 James J Duckworth
- 👤 Norbert Schnog
- 👤 Alfred B Muller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:20
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/22; G01R19/225; G01R19/02; G01R19/03; H; H03; H03F; H03F2200/00; H03F2200/261
Claims Analysis
Total Claims: 0
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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) | 1973-06-29 | 1973-12-29 | 1974-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-06-29 | 1977-12-29 | 1978-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-06-29 | 1981-12-29 | 1982-06-30 | $7700.00 | Window Closed / Lapsed |