US3564441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-pass active filter
Assignee: United Control Corp
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Filing: 1968-03-04
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Granted: 1971-02-16
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Expires: 1988-03-04
Abstract
Abstract A LOW-PASS FILTER EMPLOYS AN ACTIVE FILTER PRECEDED BY A PASSIVE FILTER, THE ACTIVE FILTER BEING AC COUPLED IN SHUNT WITH THE PASSIVE FILTER. THE PASSIVE FILTER CARRIES MOST OF THE CURRENT, THUS REDUCING THE CURRENT SUPPLIED TO THE ACTIVE FILTER AND PERMITTING THE COMPONENTS OF THE ACTIVE FILTER TO BE OF SMALLER SIZE.
Inventors
- 👤 Melvin O Eide
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:26
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/126
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |