Patent US4358712A successfully refreshed from Google Patents.
US4358712A
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Discharge lamp ballast
Assignee: ALTEX SCIENTIFIC Inc A CORP OF DE
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Filing: 1980-12-29
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Granted: 1982-11-09
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Expires: 2000-12-29
Abstract
Abstract Circuit for starting and operating a gas discharge lamp. The circuit includes a resonant circuit having a high Q during both starting and operating conditions of the lamp, thereby permitting a high lamp operating voltage to be obtained from a relatively low voltage power supply. The circuit comprises a power supply, an inductor-capacitor series-resonant circuit connected across the power supply terminals, and a lamp circuit connected in parallel with the capacitor of the series-resonant circuit, wherein the lamp circuit comprises a second capacitor connected in series with a gas discharge lamp.
Inventors
- 👤 Ludovic S. Filgas, Jr.
- 👤 Haakon T. Magnussen, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:07
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/288; H05B41/2881; H05B41/2882; H05B41/2883; H05B41/36; H05B41/38; H05B41/382; H05B41/388; Y; Y02; Y02B; Y02B20/00; Y10; Y10S; Y10S315/00; Y10S315/05; Y10S315/07
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
78 words
Apparatus for starting and operating a gas discharge lamp comprising: power supply means for supplying an alternating voltage across two power supply terminals; a series-resonant circuit, connected across the two power supply terminals, comprising an inductor and a first capacitor connected in series; and a lamp circuit, connected in parallel with the first capacitor, comprising a second capacitor connected in series with a gas discharge lamp, the second capacitor having a substantially smaller capacitance than the first capacitor.
Claim 2
Dependent Claim
78 words
Apparatus for starting and operating a gas discharge lamp comprising: power supply means for supplying an alternating voltage across two power supply terminals; a series-resonant circuit, connected across the two power supply terminals, comprising an inductor and a first capacitor connected in series; and a lamp circuit, connected in parallel with the first capacitor, comprising a second capacitor connected in series with a gas discharge lamp, the second capacitor having a substantially smaller capacitance than the first capacitor.
Claim 3
Dependent Claim
59 words
Apparatus according to claim 1 wherein the second capacitor has a capacitance substantially equal to the value of the mathematical expression ##EQU6## wherein C 1 denotes the capacitance of the first capacitor, R L denotes the effective resistance of the lamp when it is operating, and R s denotes the resistance of the series-resonant circuit at its resonant frequency.
Claim 4
Dependent Claim
43 words
Apparatus according to claim 2, further comprising: a plurality of lamp circuits, each lamp circuit comprising a capacitor connected in series with a gas discharge lamp; and switching means for selectably connecting one of the lamp circuits in parallel with the first capacitor.
Claim 5
Dependent Claim
66 words
Apparatus according to claim 3 wherein the capacitor in each lamp circuit has a capacitance substantially equal to the value of the mathematical expression ##EQU7## wherein C 1 denotes the capacitance of the first capacitor, R L denotes the effective resistance of the lamp in that lamp circuit when it is operating, and R S denotes the resistance of the series-resonant circuit at its resonant frequency.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-08 | 1986-05-10 | 1986-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-08 | 1990-05-10 | 1990-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-08 | 1994-05-10 | 1994-11-09 | $7700.00 | Window Closed / Lapsed |