US3701925A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Instantaneous starting system for discharge lamp
Assignee: Blackwell Electronics Ind Co Ltd
•
Filing: 1971-02-23
•
Granted: 1972-10-31
•
Expires: 1991-02-23
Abstract
Abstract A system for the instantaneous starting of a fluorescent lamp includes a circuit connected across the lamp having a start compensation device to apply a half-sinusoidal wave derived from a commercial power supply and oscillatory means to provide a high frequency oscillation across the lamp. The oscillatory means may include a symmetrical silicon switch (SSS) or an inversely blocking two-terminal thyristor and an oscillation adjusting inductance and capacitor. The start compensation device may be a start compensation winding wound on the same core as a current limiting winding in series with the lamp, and a start compensation diode may be connected in series with the start compensation winding. Alternatively, the diode alone may serve as the start compensation device. A thermistor having a positive characteristic may be connected in the circuit across the lamp.
Inventors
- 👤 Shunichi Nozawa
- 👤 Hisashi Kuroi
- 👤 Masamichi Hatada
- 👤 Shunsaku Fukuyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:00
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/02; H05B41/04; H05B41/042; H05B41/044; Y; Y10; Y10S; Y10S315/00; Y10S315/02; Y10S315/05
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
185 words
An instantaneous starting system for a discharge lamp of the preheat type having a pair of cathodes, comprising: a supply of alternating current power; current control means in series between said supply of power and said cathodes for limiting current to said cathodes; and circuit means connected between said cathodes across said lamp, said circuit means including start compensation means for applying a half-sinusoidal wave derived from said supply and oscillatory means including a resonant circuit and contactless switch means, said contactless switch means becoming conductive when said alternating current power reaches the breakover voltage of said switch means, and, upon becoming conductive, having a current controlled negative resistance for causing the production of said high frequency oscillation as a growing sinusoidal oscillation in said circuit means, said switch means then shifting into a region of positive resistance for causing said sinusoidal oscillation to decay, said high frequency oscillation attaining an amplitude substantially greater than the amplitude of said half sinusoidal wave whereby a relatively low starting voltage will provide sufficient preceding ionization in the lamp to promote rapid establishment of a main discharge therein.
Claim 2
Dependent Claim
185 words
An instantaneous starting system for a discharge lamp of the preheat type having a pair of cathodes, comprising: a supply of alternating current power; current control means in series between said supply of power and said cathodes for limiting current to said cathodes; and circuit means connected between said cathodes across said lamp, said circuit means including start compensation means for applying a half-sinusoidal wave derived from said supply and oscillatory means including a resonant circuit and contactless switch means, said contactless switch means becoming conductive when said alternating current power reaches the breakover voltage of said switch means, and, upon becoming conductive, having a current controlled negative resistance for causing the production of said high frequency oscillation as a growing sinusoidal oscillation in said circuit means, said switch means then shifting into a region of positive resistance for causing said sinusoidal oscillation to decay, said high frequency oscillation attaining an amplitude substantially greater than the amplitude of said half sinusoidal wave whereby a relatively low starting voltage will provide sufficient preceding ionization in the lamp to promote rapid establishment of a main discharge therein.
Claim 3
Dependent Claim
54 words
An instantaneous starting system as recited in claim 1, wherein said current control means and said circuit means are so constructed that said lamp, during a preheat period, is provided with a preheat current substantially greater than the upper limit of the preheat current rating of the lamp for all practical supply voltage fluctuations.
Claim 4
Dependent Claim
33 words
An instantaneous starting system according to claim 2, wherein said start compensation means comprises a start compensation winding and said current control means comprises a current control winding on a common magnetic path.
Claim 5
Dependent Claim
25 words
An instantaneous starting system according to claim 3, wherein said magnetic path is a saturable path and said windings are wound thereon with opposite polarity.
Claim 6
Dependent Claim
56 words
An instantaneous starting system according to claim 3, wherein said contactless switch means comprises a symmetrical contactless switch and said resonant circuit includes an oscillation adjusting inductance in series with said start compensation winding and an oscillation adjusting capacitor connected across the series circuit formed by said start compensation winding, symmetrical switch, and oscillation adjusting inductance.
Claim 7
Dependent Claim
26 words
An instantaneous starting system according to claim 5, wherein said circuit means further comprises a thermistor having a positive characteristic in series with said symmetrical switch.
Claim 8
Dependent Claim
48 words
An instantaneous starting system according to claim 3, wherein said magnetic path comprises a core having a small high frequency loss and wherein said contactless switch means comprises a symmetrical contactless switch and said resonant circuit includes an oscillation adjusting inductance in series with said start compensation winding.
Claim 9
Dependent Claim
26 words
An instantaneous starting system according to claim 7, wherein said circuit means further comprises a thermistor having a positive characteristic in series with said symmetrical switch.
Claim 10
Dependent Claim
54 words
An instantaneous starting system according to claim 3, wherein said contactless switch means comprises a symmetrical contactless switch and said resonant circuit comprises an oscillation adjusting inductance In series with said start compensation winding and an oscillation adjusting capacitor connected across the series circuit formed by said symmetrical switch and said oscillation adjusting inductance.
Claim 11
Dependent Claim
26 words
An instantaneous starting system according to claim 9, wherein said circuit means further comprises a thermistor having a positive characteristic in series with said symmetrical switch.
Claim 12
Dependent Claim
26 words
An instantaneous starting system according to claim 3, wherein said circuit means further comprises a start compensation diode connected in series with said start compensation winding.
Claim 13
Dependent Claim
63 words
An instantaneous starting system according to claim 11, wherein said contactless switch means comprises a symmetrical contactless switch and said resonant circuit comprises an oscillation adjusting inductance in series with said start compensation winding and start compensation diode and an oscillation adjusting capacitor connected across the series circuit formed by said start compensation winding, start compensation diode, symmetrical switch, and oscillation adjusting inductance.
Claim 14
Dependent Claim
54 words
An instantaneous starting system according to claim 3, wherein said contactless switch means comprises an inversely blocking two-terminal thyristor and said resonant circuit comprises an oscillation adjusting inductance in series with said start compensation winding and an oscillation adjusting capacitor connected across the series circuit formed by said start compensation winding, thyristor, and inductance.
Claim 15
Dependent Claim
25 words
An instantaneous starting system according to claim 13, wherein said circuit means further comprises a thermistor having a positive characteristic in series with said thyristor.
Claim 16
Dependent Claim
44 words
An instantaneous starting system according to claim 3, wherein said contactless switch means comprises a symmetrical contactless switch and said circuit means further comprises a thermistor having a positive characteristic, said start compensation winding, switch, and thermistor being connected in series between said cathodes.
Claim 17
Dependent Claim
29 words
An instantaneous starting system according to claim 3, wherein said contactless switch means comprises a symmetrical contactless switch connected in series with said start compensation winding between said cathodes.
Claim 18
Dependent Claim
18 words
An instantaneous starting system according to claim 2, wherein said start compensation means comprises a start compensation diode.
References Cited (Backward Citations)
US2526853A
Cited
US2964676A
Cited
US3089981A
Cited
US3249806A
Cited
US3351807A
Cited
US3476976A
Cited
US3522475A
Cited
US3479559A
Cited
US3501674A
Cited
US3517254A
Cited
US3553526A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-31 | 1976-05-01 | 1976-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-31 | 1980-05-01 | 1980-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-31 | 1984-05-01 | 1984-10-31 | $7700.00 | Window Closed / Lapsed |