US4353010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transistor drive scheme for fluorscent lamp ballast
Assignee: Osram Sylvania Inc
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Filing: 1980-12-19
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Granted: 1982-10-05
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Expires: 2000-12-19
Abstract
Abstract An improved drive scheme for a pair of push-pull inverter transistors in an electronic ballast circuit. The inverter output is coupled through a series resonant circuit comprising a capacitor and the primary winding of an output transformer. The resonant circuit is coupled to the inverter output through an additional winding on the primary of an interstage so that a component of the loop current is fed back to the bases of the push-pull transistors, thereby compensating for phase errors in the drive signal applied at the inverter input.
Inventors
- 👤 William C. Knoll
- 👤 David L. Bay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:32
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/2825; H05B41/2827; Y; Y10; Y10S; Y10S315/00; Y10S315/07
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
119 words
In an electronic ballast circuit including a transistor inverter and an interstage transformer, said interstage transformer including a first primary winding adapted to be coupled in series with at least one lamp filament for developing a feedback signal derived from the filament current and including at least one secondary winding coupled to an input of the inverter, an improved transistor drive scheme including a phase-feedback winding on the primary of the interstage winding, said phase feedback winding coupled in series with an inverter output circuit loop for developing a phase-feedback signal in proportion to the output circuit loop current, which phase feedback signal is coupled to an input of the inverter via a secondary winding on the interstage transformer.
Claim 2
Dependent Claim
119 words
In an electronic ballast circuit including a transistor inverter and an interstage transformer, said interstage transformer including a first primary winding adapted to be coupled in series with at least one lamp filament for developing a feedback signal derived from the filament current and including at least one secondary winding coupled to an input of the inverter, an improved transistor drive scheme including a phase-feedback winding on the primary of the interstage winding, said phase feedback winding coupled in series with an inverter output circuit loop for developing a phase-feedback signal in proportion to the output circuit loop current, which phase feedback signal is coupled to an input of the inverter via a secondary winding on the interstage transformer.
Claim 3
Dependent Claim
129 words
In an electronic ballast circuit for providing current to a lamp filament, said ballast circuit including an inverter, an output transformer having a primary winding coupled to the inverter output and at least one secondary winding adapted to supply current to a lamp filament, and an interstage transformer having a primary winding adapted to be coupled in a loop with at least one filament and a secondary winding of the output transformer so as to develop a filament feedback signal in proportion to a filament current and having a secondary winding coupled to an inverter input, the improvement comprising a phase-feedback winding on primary of the interstage transformer and coupled in series with the inverter output circuit loop for developing a phase-feedback signal derived from the output loop current.
Claim 4
Dependent Claim
129 words
In an electronic ballast circuit for providing current to a lamp filament, said ballast circuit including an inverter, an output transformer having a primary winding coupled to the inverter output and at least one secondary winding adapted to supply current to a lamp filament, and an interstage transformer having a primary winding adapted to be coupled in a loop with at least one filament and a secondary winding of the output transformer so as to develop a filament feedback signal in proportion to a filament current and having a secondary winding coupled to an inverter input, the improvement comprising a phase-feedback winding on primary of the interstage transformer and coupled in series with the inverter output circuit loop for developing a phase-feedback signal derived from the output loop current.
References Cited (Backward Citations)
US4075476A
Cited
US4188661A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-04 | 1986-04-05 | 1986-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-04 | 1990-04-05 | 1990-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-04 | 1994-04-05 | 1994-10-05 | $7700.00 | Window Closed / Lapsed |