US3629648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transistorized fluorescent tube operating circuit
Assignee: Individual
•
Filing: 1969-07-31
•
Granted: 1971-12-21
•
Expires: 1989-07-31
Abstract
Abstract A circuit for operating fluorescent tubes ranging from 8 to 40 watts, the circuit being supplied by either direct or alternating current. The circuit components are arranged so that input current flows through a series path defined by the primary winding of a transformer and the emitter and collector junctions of a transistor. The secondary winding of the transformer serves to provide energy for lighting the fluorescent tube and further serves to provide a feedback current for biasing the transistor.
Inventors
- 👤 Brent W Brown
- 👤 Edward B Rich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:59
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/2821; Y; Y10; Y10S; Y10S315/00; Y10S315/07
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
119 words
A circuit for powering fluorescent tubes, the circuit comprising: first and second input terminals; a transformer having a primary and a secondary winding; a transistor; a primary series circuit defined by the primary winding of the transformer, the transistor, and the first and second input terminals, a secondary series circuit defined by the secondary winding of the transformer, the fIrst and second input terminals, and the first and second filaments of a fluorescent tube; and means connecting said transistor to said secondary series circuit for biasing said transistor; the secondary series circuit being defined in such a manner that the ionization of the fluorescent tube shunts the secondary winding of the transformer and reduces the bias on the transistor.
Claim 2
Dependent Claim
119 words
A circuit for powering fluorescent tubes, the circuit comprising: first and second input terminals; a transformer having a primary and a secondary winding; a transistor; a primary series circuit defined by the primary winding of the transformer, the transistor, and the first and second input terminals, a secondary series circuit defined by the secondary winding of the transformer, the fIrst and second input terminals, and the first and second filaments of a fluorescent tube; and means connecting said transistor to said secondary series circuit for biasing said transistor; the secondary series circuit being defined in such a manner that the ionization of the fluorescent tube shunts the secondary winding of the transformer and reduces the bias on the transistor.
Claim 3
Dependent Claim
25 words
The circuit as described in claim 1 and further comprising resistor means for biasing the base of said transistor from one of the input terminals.
Claim 4
Dependent Claim
33 words
The circuit as defined in claim 2 wherein the transistor is a PNP-transistor wherein the resistor means for biasing the transistor is connected between said second terminal and the base of the transistor.
Claim 5
Dependent Claim
28 words
The circuit as defined in claim 1 and further comprising a diode connected between the first input terminal and the primary winding of the transformer for cross-polarity protection.
Claim 6
Dependent Claim
25 words
The circuit as defined in claim 1 and further comprising a capacitor connected between said input terminal and the first filament of said fluorescent tube.
Claim 7
Dependent Claim
36 words
The invention as defined in claim 1 and further comprising a full-wave rectifier associated with said first and second input terminals for providing the circuit with capabilities of operating from either AC or DC powering means.
Claim 8
Dependent Claim
47 words
The circuit as defined in claim 1 and further comprising at least one filament winding on the secondary side of said transformer and means for connecting said filament winding to respective filaments of fluorescent tubes in order to power a plurality of tubes from a single ballast.
Claim 9
Dependent Claim
55 words
The invention as defined in claim 7 wherein said secondary winding is connected between one filament of a first fluorescent tube and one filament of a further fluorescent tube and wherein one filament winding is provided for each tube in excess of one, each filament winding connecting, in parallel, the intermediate filaments of said tubes.
Claim 10
Dependent Claim
25 words
The invention as defined in claim 1 and further comprising a plurality of transistors shunted so as to increase the wattage capability of said circuit.
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) | 1974-12-20 | 1975-06-21 | 1975-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-20 | 1979-06-21 | 1979-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-20 | 1983-06-21 | 1983-12-21 | $7700.00 | Window Closed / Lapsed |