US3588624A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Demagnetizing circuit
Assignee: AT&T Inc
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Filing: 1969-11-10
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Granted: 1971-06-28
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Expires: 1989-11-10
Abstract
Abstract A CIRCUIT FOR PRODUCING A DECREASING MAGNETIC FIELD TO DEMAGNETIZE A MAGNETIC OBJECT OR MATERIAL INCLKUDES AN OSCILLATOR IN SERIES WITH A RADIANT ENERGY CONTROLLED RESISTOR AND A COIL. A PULSE GENERATOR EXCITES A LAMP TO DECREASE THE RESISTANCE OF THE RADIANT ENERGY CONTROLLED RESISTOR TO PRODUCE A MAGNETIC FIELD IN THE COIL. THE OSCILLATOR IS SELECTED TO HAVE A FREQUENCY TO PRODUCE A PREDETERMINED NUMBER OF CYCLES DURING THE INHERENT DECAY TIME OF THE RADIANT ENERGY CONTROLLED RESISTOR AND LAMP.
Inventors
- 👤 William H Marvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:10
CPC Classifications
H; H01; H01F; H01F13/00; H01F13/006
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 |