US3882354A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inverter ballast circuit for fluorescent lamp
Assignee: MASTER CRAFT BOAT Co (TN CORPORATION)
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Filing: 1973-07-23
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Granted: 1975-05-06
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Expires: 1993-07-23
Abstract
Abstract An oscillator including a single transistor is connected in circuit with the primary winding of a stepup transformer. The terminals of a fluorescent lamp are connected between the primary and secondary of the transformer. One filament of the lamp is connected in the base circuit of the transistor. The filament acts as a constant current device to limit the current flowing in the base circuit and thereby permit the inverter to operate over a wide range of input voltages.
Inventors
- 👤 Randall L May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:23
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/53; H02M7/537; H02M7/5383; H02M7/53846; H02M7/53862; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/295; H05B41/298; H05B41/2981; H05B41/2983; Y; Y10; Y10S; Y10S315/00; Y10S315/05; Y10S315/07
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
200 words
An inverter ballast circuit for energizing a fluorescent lamp from a source of direct voltage comprising: a transistor having a collector, an emitter and a base terminal, said collector being connected to one terminal of said source; a transformer having a primary winding and a secondary winding, said primary winding including an input section and a feedback section; means for connecting said lamp between said primary and secondary winding; means for connecting said feedback winding section of said transformer in series with a filament of said lamp and with the base-emitter junction of said transistor, the emitter junction of said transistor being further connected in circuit with said input winding section of said primary winding of said transformer such that current flowing through said transistor will energize said input winding section to induce a voltage in said secondary and in said feedback winding section, said input winding and said transistor being arranged in an oscillatory circuit, whereby as the current in said input winding section increases, said filament will limit the input current to said transistor, said filament being characterized as being a substantially constant current element over its operating range, thereby to control the output voltage of said transistor.
Claim 2
Dependent Claim
200 words
An inverter ballast circuit for energizing a fluorescent lamp from a source of direct voltage comprising: a transistor having a collector, an emitter and a base terminal, said collector being connected to one terminal of said source; a transformer having a primary winding and a secondary winding, said primary winding including an input section and a feedback section; means for connecting said lamp between said primary and secondary winding; means for connecting said feedback winding section of said transformer in series with a filament of said lamp and with the base-emitter junction of said transistor, the emitter junction of said transistor being further connected in circuit with said input winding section of said primary winding of said transformer such that current flowing through said transistor will energize said input winding section to induce a voltage in said secondary and in said feedback winding section, said input winding and said transistor being arranged in an oscillatory circuit, whereby as the current in said input winding section increases, said filament will limit the input current to said transistor, said filament being characterized as being a substantially constant current element over its operating range, thereby to control the output voltage of said transistor.
Claim 3
Dependent Claim
158 words
In an inverter ballast circuit for energizing a fluorescent lamp from a source of direct voltage with an oscillating circuit having an active element and controlled by an input current, the improvement comprising: transformer means including a primary winding and a secondary winding, said primary winding including an input winding section and a feedback winding section; means connecting said lamp between said secondary and said primary windings; and means connecting said feedback winding section, a filament of said lamp and said active element in circuit such that the input current controlling said active element passes from said feedback winding through said filament, whereby as the magnitude of said voltage source increases, the current through said filament increases to substantially increase the resistance thereof, thereby to keep the input current to said active element substantially constant whereby a substantially constant voltage is applied and energizes said lamp independent of the magnitude of said voltage source over a given range.
Claim 4
Dependent Claim
158 words
In an inverter ballast circuit for energizing a fluorescent lamp from a source of direct voltage with an oscillating circuit having an active element and controlled by an input current, the improvement comprising: transformer means including a primary winding and a secondary winding, said primary winding including an input winding section and a feedback winding section; means connecting said lamp between said secondary and said primary windings; and means connecting said feedback winding section, a filament of said lamp and said active element in circuit such that the input current controlling said active element passes from said feedback winding through said filament, whereby as the magnitude of said voltage source increases, the current through said filament increases to substantially increase the resistance thereof, thereby to keep the input current to said active element substantially constant whereby a substantially constant voltage is applied and energizes said lamp independent of the magnitude of said voltage source over a given range.
References Cited (Backward Citations)
US3432723A
Cited
US3629648A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |