US3771068A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant wattage autotransformer ballast for high pressure sodium lamp
Assignee: GTE Sylvania Inc
•
Filing: 1973-01-02
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Granted: 1973-11-06
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Expires: 1993-01-02
Abstract
Abstract A ballast for a high pressure sodium lamp includes a constant wattage autotransformer with a series capacitor, of 10 microfarads for example, between the autotransformer secondary and one lamp terminal, and an arc sustaining capacitor of lower value connected in parallel with the secondary.
Inventors
- 👤 F Paget
- 👤 J Avallon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:12
CPC Classifications
H; H01; H01F; H01F38/00; H01F38/08; H01F38/10; H05; H05B; H05B41/00; H05B41/14; H05B41/16; H05B41/20; H05B41/23; H05B41/231
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
128 words
A ballast for a high pressure sodium lamp comprising: input terminals for connection to alternating current lines, output terminals for connection across a high pressure sodium lamp, a constant wattage autotransformer having a primary winding connected to the input terminals and one output terminal, and a secondary having a connection to the other output terminal, a series capacitor in the connection to the other output terminal, and an arc sustaining capacitor connected to one of the input terminals in parallel with the secondary winding of the autotransformer and having a value to resonate therewith, whereby to produce a fast rise in the voltage at the output terminals at the beginning of each alternating half cycle, thereby to sustain and stabilize the arc in a high pressuRe sodium lamp.
Claim 2
Dependent Claim
128 words
A ballast for a high pressure sodium lamp comprising: input terminals for connection to alternating current lines, output terminals for connection across a high pressure sodium lamp, a constant wattage autotransformer having a primary winding connected to the input terminals and one output terminal, and a secondary having a connection to the other output terminal, a series capacitor in the connection to the other output terminal, and an arc sustaining capacitor connected to one of the input terminals in parallel with the secondary winding of the autotransformer and having a value to resonate therewith, whereby to produce a fast rise in the voltage at the output terminals at the beginning of each alternating half cycle, thereby to sustain and stabilize the arc in a high pressuRe sodium lamp.
Claim 3
Dependent Claim
31 words
A ballast according to claim 1 wherein the autotransformer and series capacitor are sealed in a housing and the sustaining capacitor is connected to the ballast terminals externally of the housing.
Claim 4
Dependent Claim
18 words
A ballast according to claim 1 wherein the sustaining capacitor has a lower value than the series capacitor.
Claim 5
Dependent Claim
18 words
A ballast according to claim 1 wherein the sustaining capacitor has a value between 0.1 and 10 microfarads.
Claim 6
Dependent Claim
18 words
A ballast according to claim 4 wherein the sustaining capacitor has a value of 0.4 to 1 microfarad.
References Cited (Backward Citations)
US2910623A
Cited
US3029363A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |