US3679932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescent lamp idling circuit
Assignee: Pitney Bowes Inc
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Filing: 1971-01-19
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Granted: 1972-07-25
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Expires: 1991-01-19
Abstract
Abstract A circuit is described for operating a fluorescent lamp at a low power consumption idling level. The circuit provides a capacitive impedance in series between the fluorescent lamp and an AC supply. The capacitive impedance is selected to reduce the current flow through the lamp to a low idling level, yet full illumination may be quickly and reliably restored by effectively removing the capacitive impedance.
Inventors
- 👤 James P Murphy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:28
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/36; H05B41/38; H05B41/40; H05B41/42
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
141 words
An apparatus for illuminating a gAs discharge lamp powered by an AC source and wherein a starter circuit is employed including a series connected ballast inductor and a starter component, the improvements comprising: an idling circuit having low loss and high capacitive reactance characteristics, said idling circuit including a capacitor connected in series between the lamp and the AC source and having a capacitive reactance substantially larger than the inductive reactance of the ballast inductor, the reactance of said capacitor being sufficient, in and of itself, to limit the current flow through the lamp to an idling level sufficient to sustain a reduced power discharge in said lamp, and a switch connected across said capacitor, said switch selectively operated to shunt said capacitor and thereby increase the current through the lamp to the level required for normal illumination by the lamp.
Claim 2
Independent Claim
141 words
An apparatus for illuminating a gAs discharge lamp powered by an AC source and wherein a starter circuit is employed including a series connected ballast inductor and a starter component, the improvements comprising: an idling circuit having low loss and high capacitive reactance characteristics, said idling circuit including a capacitor connected in series between the lamp and the AC source and having a capacitive reactance substantially larger than the inductive reactance of the ballast inductor, the reactance of said capacitor being sufficient, in and of itself, to limit the current flow through the lamp to an idling level sufficient to sustain a reduced power discharge in said lamp, and a switch connected across said capacitor, said switch selectively operated to shunt said capacitor and thereby increase the current through the lamp to the level required for normal illumination by the lamp.
Claim 3
Dependent Claim
52 words
The improvement defined in claim 1, wherein said idling circuit further includes a resistor connected in series with said capacitor across said switch, said resistor having a resistance value sufficient to reduce capacitive transient currents when said switch is operated, said resistance value being substantially less than the reactance of said capacitor.
Claim 4
Dependent Claim
27 words
The improvement defined in claim 1, wherein the capacitive reactance of said capacitor exceeds the inductive reactance of the ballast inductor by a factor of approximately 10.
Claim 5
Dependent Claim
19 words
The improvement defined in claim 1, wherein the capacitance of said capacitor is on the order of one microfarad.
References Cited (Backward Citations)
US3086140A
Cited
US2492575A
Cited
US3201645A
Cited
US3130347A
Cited
US3264518A
Cited
US3463964A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |