US3558995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bidirectional thyristor switching on-off control systems for an inductive load
Assignee: Cutler Hammer Inc
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Filing: 1967-08-24
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Granted: 1971-01-26
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Expires: 1987-08-24
Abstract
Abstract AN "ON-OFF" CONTROL SYSTEM WHICH RESPONDS TO DISCRETE, PRESETTABLE VALUE OF A GRADUALLY VARYING CONDITION SUCH AS TEMPERATURE, LIGHT, HUMIDITY, MANUALLY OR AUTOMATICALLY VARIABLE RESISTOR, ETC. TO ENERGIZE OR DEENERGIZE AN INDUCTIVE LOAD. BY INTERCHANGING THE RESISTANCE AND CAPACITANCE DEVICES FROM THEIR NORMAL POSITIONS IN THE FIRING CONTROL CIRCUIT OF A SOLID STATE GATING TYPE POWER CONTROL ELEMENT OF THE FULL-WAVE SWITCHING TYPE SUCH AS A "QUADRAC" OR "TRIAC," THE POWER WILL BE SWITCHED EITHER ON OR OFF, AT LEAST FOR INDUCTIVE LOADS, AS A FUNCTION OF THE VALUE OF THE RESISTANCE.
Inventors
- 👤 Merle R Swinehart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:46
CPC Classifications
H; H02; H02H; H02H5/00; H02H5/04; H02H5/042; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1906; G05D23/1909; G05D23/20; G05D23/24; G05F; G05F1/00; G05F1/10; G05F1/12; G05F1/40; G05F1/44; G05F1/45; G05F1/452
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |