US3703677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescent lamp inverter circuit
Assignee: Thorn Electronics Ltd
•
Filing: 1968-06-19
•
Granted: 1972-11-21
•
Expires: 1988-06-19
Abstract
Abstract There is disclosed an inverter circuit particularly, but not exclusively, for operating fluorescent lamps. This circuit has a transformer to the primary of which is to be supplied a periodically switched D.C., a load being connected across the secondary. The transformer has an annular core having at least one air gap in it and two limbs projecting towards one another from opposing parts of the annulus and separated by an air gap. The primary and secondary windings surround the annulus on opposite sides of the limbs.
Inventors
- 👤 Victor Farrow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:14
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/2821; H05B41/2822; H01; H01F; H01F38/00; H01F38/08; H01F38/10; Y; Y10; Y10S; Y10S315/00; Y10S315/07
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
123 words
An inverter circuit comprising D. C. input terminals, A.C. output terminals, a transformer, a coupling between said input terminals and the primary winding of said transformer, switching means in said coupling, and connections between the secondary winding of said transformer and said output terminals, said transformer having an annular core, at least one air gap in said annular core, and two limbs projecting toward one another from opposing parts of said annular core and having an air gap between their ends, said primary and secondary windings surrounding said annular core on opposite sides of said limbs, and a primaryshunting condenser, wherein said limbs have a dimension greater than said annulus in a direction perpendicular to a plane through the axes of said windings.
Claim 2
Dependent Claim
123 words
An inverter circuit comprising D. C. input terminals, A.C. output terminals, a transformer, a coupling between said input terminals and the primary winding of said transformer, switching means in said coupling, and connections between the secondary winding of said transformer and said output terminals, said transformer having an annular core, at least one air gap in said annular core, and two limbs projecting toward one another from opposing parts of said annular core and having an air gap between their ends, said primary and secondary windings surrounding said annular core on opposite sides of said limbs, and a primaryshunting condenser, wherein said limbs have a dimension greater than said annulus in a direction perpendicular to a plane through the axes of said windings.
References Cited (Backward Citations)
US1353711A
Cited
US2170446A
Cited
FR1035405A
Cited
US2949565A
Cited
US3008068A
Cited
NL6605747A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |