US3599037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gaslamp lead ballast circuit having feedback control
Assignee: Xerox Corp
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Filing: 1969-05-01
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Granted: 1971-08-10
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Expires: 1989-05-01
Abstract
Abstract Lead ballast circuits for operating gas discharge lamps are disclosed. The circuits employ a variable inductor, such as a linear inductor or saturable reactor, in series with a capacitor as the means for limiting the lamp current. The effective impedance of the circuit is basically capacitive and the variable inductor is used to vary that effective capacitance. A feedback path between a lamp and saturable reactor is also disclosed.
Inventors
- 👤 Robert E Grace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:41
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/36; H05B41/38; H05B41/39; H05B41/391; B; B65; B65G; B65G2201/00; B65G2201/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
124 words
A lead ballast circuit for operating a gas discharge lamp comprising a saturable reactor including primary and control coils with said primary coil coupled in series with a capacitor and said lamp wherein the capacitance is such that the effective impedance of the circuit is capacitive, a lead-peaked autotransformer capable of providing voltages for lamp ignition including input terminals for coupling to an alternating current voltage source and first and second output terminals coupled to said capacitor and lamp, respectively, and feedback means for varying lamp current in response to light output including means adjacent said lamp and coupled to said control coil for detecting light output and varying control coil current to change circuit impedance and lamp current whereby light output is varied.
Claim 2
Dependent Claim
124 words
A lead ballast circuit for operating a gas discharge lamp comprising a saturable reactor including primary and control coils with said primary coil coupled in series with a capacitor and said lamp wherein the capacitance is such that the effective impedance of the circuit is capacitive, a lead-peaked autotransformer capable of providing voltages for lamp ignition including input terminals for coupling to an alternating current voltage source and first and second output terminals coupled to said capacitor and lamp, respectively, and feedback means for varying lamp current in response to light output including means adjacent said lamp and coupled to said control coil for detecting light output and varying control coil current to change circuit impedance and lamp current whereby light output is varied.
Claim 3
Dependent Claim
36 words
The circuit of claim 1 further including a shunt inductor coupled in parallel with the primary coil of said saturable reactor and having an inductance value such that the effective impedance of the circuit is capacitive.
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) | 1974-08-09 | 1975-02-08 | 1975-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-09 | 1979-02-08 | 1979-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-09 | 1983-02-08 | 1983-08-10 | $7700.00 | Window Closed / Lapsed |