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US5068576A
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US
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Remote control of fluorescent lamp ballast using power flow interruption coding with means to maintain filament voltage substantially constant as the lamp voltage decreases
Assignee: ELECTRONIC BOLLAST TECHNOLOGY INCORPORATED
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Filing: 1990-08-13
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Granted: 1991-11-26
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Expires: 2010-08-13
Abstract
Abstract A dimming ballast system wherein the light output of the lamp is controlled by a remote source. The ballast output voltage is regulated by a voltage control feedback loop, the dimming function being achieved by varying the set point of the control loop. The remote control signal, coded by interrupting the current flow to the ballast for a short period, is processed digitally by a microcomputer which generates information to vary the control set point. Circuit means are provided to control the filament voltage of the fluorescent lamps such that as the lamps are dimmed down, the filament voltage is maintained or slightly increased, thus prolonging lamp life and stabilizing the lamp light output.
Inventors
- 👤 Feng-Kang Hu
- 👤 Chung M. Lau
- 👤 Kevin Yang
- 👤 Joshau S. Zhu
- 👤 Peter S. Shen
- 👤 Thomas C. Jednacz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:50
CPC Classifications
H; H02; H02M; H02M5/00; H02M5/02; H02M5/04; H02M5/22; H02M5/25; H02M5/257; H02M5/2573; H02M5/2576; H05; H05B; H05B41/00; H05B41/14; H05B41/36; H05B41/38; H05B41/39; H05B41/392; H05B41/3921; H05B41/3927; Y; Y10; Y10S; Y10S315/00; Y10S315/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
203 words
A dimmable fluorescent lamp ballast system comprising: means for providing a first AC voltage signal; encoder means connected to said AC voltage for providing a cyclical signal, each cycle containing a missing pulse; decoder means responsive to said signal for providing a DC voltage signal having a magnitude predetermined by the time period between missing pulses in successive cycles of said pulse train; a fluorescent lamp having filament means associated therewith; first circuit means responsive to said DC voltage signal for generating a first AC signal having a magnitude proportional to the magnitude of said DC voltage signal, said first AC signal being coupled to said fluorescent lamp; and second circuit means responsive to said DC voltage signal for generating a second AC voltage signal having a magnitude proportional to the resonant frequency of said second circuit means, said second AC voltage signal being applied to said lamp filament means, a decrease in the magnitude of said first AC voltage signal from a first level to a second level causing said second circuit means to maintain the magnitude of said second AC voltage signal at a value at least equal to the value when said first AC signal was at said first level.
Claim 2
Dependent Claim
203 words
A dimmable fluorescent lamp ballast system comprising: means for providing a first AC voltage signal; encoder means connected to said AC voltage for providing a cyclical signal, each cycle containing a missing pulse; decoder means responsive to said signal for providing a DC voltage signal having a magnitude predetermined by the time period between missing pulses in successive cycles of said pulse train; a fluorescent lamp having filament means associated therewith; first circuit means responsive to said DC voltage signal for generating a first AC signal having a magnitude proportional to the magnitude of said DC voltage signal, said first AC signal being coupled to said fluorescent lamp; and second circuit means responsive to said DC voltage signal for generating a second AC voltage signal having a magnitude proportional to the resonant frequency of said second circuit means, said second AC voltage signal being applied to said lamp filament means, a decrease in the magnitude of said first AC voltage signal from a first level to a second level causing said second circuit means to maintain the magnitude of said second AC voltage signal at a value at least equal to the value when said first AC signal was at said first level.
Claim 3
Dependent Claim
16 words
The ballast system of claim 1 wherein said decoder means is remote from said encoding means.
Claim 4
Dependent Claim
21 words
The ballast system of claim 1 wherein the time period between missing pulses is adjusted between 1 and n+1 discrete levels.
Claim 5
Dependent Claim
20 words
The ballast system of claim 3 wherein each discrete level corresponds to a selected light output from said fluorescent lamp.
Claim 6
Dependent Claim
25 words
The ballast system of claim 4 wherein the magnitude of said first voltage signal enables said fluorescent lamp to operate at said selected light output.
Claim 7
Dependent Claim
13 words
The ballast system of claim 1 wherein said encoder means comprises a microcomputer.
Claim 8
Dependent Claim
13 words
The ballast system of claim 6 wherein said decoder means comprises a microcomputer.
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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) | 1994-11-25 | 1995-05-27 | 1995-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-25 | 1999-05-27 | 1999-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-25 | 2003-05-27 | 2003-11-26 | $7700.00 | Window Closed / Lapsed |