US3588889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical signaling system including selectively variable impedance device
Assignee: Individual
•
Filing: 1968-06-26
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Granted: 1971-06-28
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Expires: 1988-06-26
Abstract
Abstract AN ELECTRICAL SIGNALING SYSTEM INCLUDING A NONVOLTAGEGENERATING CHANGEABLE VALUE IMPEDANCE DEVICE WHICH IS ACTUATABLE TO PRODUCE AT A PAIR OF OUTPUT TERMINALS DIFFERENT SELECT IMPEDANCE VALUES, AND AN ANALYZING CIRCUIT REMOTE FROM AND CONNECTED TO THE DEVICE WHICH PRODUCES DIFFERENT OUTPUT SIGNALS IN RESPONSE TO DIFFERENT IMPEDANCE VALUES PRODUCED AT THE OUTPUT TERMINALS OF THE DEVICE. A SINGLE DC VOLTAGE SOURCE LOCATED ADJACENT THE ANALYZING CIRCUIT SUPPLIES ALL ELECTRICAL POWER REQUIRED IN THE SYSTEM.
Inventors
- 👤 Joseph Schulein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:23
CPC Classifications
G; G08; G08B; G08B25/00; G08B25/01; G08B25/018
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) | 1974-06-27 | 1974-12-27 | 1975-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-27 | 1978-12-27 | 1979-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-27 | 1982-12-27 | 1983-06-28 | $7700.00 | Window Closed / Lapsed |