US3710177A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescent lamp circuit driven initially at lower voltage and higher frequency
Assignee: Joy Global Industries Ltd
•
Filing: 1971-11-09
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Granted: 1973-01-09
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Expires: 1991-11-09
Abstract
Abstract A circuit for fluorescent lamps includes an inverter which incorporates means such as temperature dependent elements or switches whereby the voltage from the inverter is lower but at a higher frequency initially than during normal running. This inverter feeds a plurality of lamps, each having associated circuit elements which are resonant or semi-resonant at the higher frequency, to facilitate the lamps conducting.
Inventors
- 👤 R Ward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:10
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/02; H05B41/04; H05B41/042; Y; Y10; Y10S; Y10S315/00; Y10S315/02; Y10S315/05
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
91 words
A circuit comprising an element such as a fluorescent lamp which has to be conditioned to conduct, circuit elements connected, one in series and one in parallel, with the firstmentioned element and designed to resonate at a resonant frequency and an inverter for supplying the lamp and said circuit elements with a voltage at a frequency less than the resonant frequency, the improvement residing in that said inverter incorporates means whereby it can deliver a reduced voltage at a frequency nearer the resonant frequency to facilitate conditioning of the first-mentioned element.
Claim 2
Dependent Claim
91 words
A circuit comprising an element such as a fluorescent lamp which has to be conditioned to conduct, circuit elements connected, one in series and one in parallel, with the firstmentioned element and designed to resonate at a resonant frequency and an inverter for supplying the lamp and said circuit elements with a voltage at a frequency less than the resonant frequency, the improvement residing in that said inverter incorporates means whereby it can deliver a reduced voltage at a frequency nearer the resonant frequency to facilitate conditioning of the first-mentioned element.
Claim 3
Dependent Claim
66 words
A circuit as claimed in claim 1 wherein said first-mentioned element is a gaseous discharge device having at least one filament and the said circuit elements are a capacitor and an inductor connected in series with each other and with the said at least one filament with the capacitor being connected across said discharge device so it is shunted by the device when the device conducts.
Claim 4
Dependent Claim
15 words
A circuit as claimed in claim 2 in which said means are temperature dependent elements.
Claim 5
Dependent Claim
13 words
A circuit as claimed in claim 2 in which said means are switches.
Claim 6
Dependent Claim
42 words
A circuit as claimed in claim 2 in which said inverter comprises an astable multivibrator having switched means for varying the pulse repetition frequency, thyristors rendered conductive by said multivibrator, and output means including means for varying the output from said thyristors.
References Cited (Backward Citations)
US2964676A
Cited
US3448335A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |