Patent US1926283A successfully refreshed from Google Patents.
Patent US5218272A successfully refreshed from Google Patents.
US5218272A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid state electronic ballast system for fluorescent lamps
Assignee: Robertshaw Controls Co
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Filing: 1991-12-30
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Granted: 1993-06-08
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Expires: 2011-12-30
Abstract
Abstract A high power factor ballast circuit for use with fluorescent lamps consisting of a power factor correcting inductor periodically saturated to store pulses of direct current energy and periodically discharge same at a regular periodic rate to power the fluorescent lamp. A bistable flip-flop circuit and an associated solid state switching device combine to periodically control the saturation and discharge of the inductor.
Inventors
- 👤 William H. Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:08
CPC Classifications
H; H02; H02M; H02M1/00; H02M1/42; H02M1/4208; H02M1/4225; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/145; H02M3/155; H02M3/156; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/282; H05B41/2821; H05B41/2824; Y; Y02; Y02B; Y02B70/00; Y02B70/10; Y10; Y10S; Y10S315/00; Y10S315/05
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
290 words
A high power factor ballast circuit connected between a source of alternating current and a fluorescent lamp, said ballast circuit comprising: a rectifier circuit connected to said power source operated to produce direct current from said alternating current source; a first circuit connection including a power factor correcting saturable inductor and a capacitor connected in series between said rectifier circuit and said fluorescent lamp, said saturable inductor storing energy from said rectifier circuit until saturated; a second circuit connection directly between said fluorescent lamp and said rectifier circuit; a second capacitor connected between said first and second circuit connections; a first solid state switching device connected to a junction between said saturable inductor and said first capacitor and said direct connection, in parallel with said fluorescent lamp; a bistable flip-flop circuit including a first output connected to said solid state switching device; a free running oscillator connected to a first input of said bistable flip-flop circuit; said bistable flip-flop circuit normally operated in response to said free running oscillator to periodically operate said solid state switching device; current sensing means in series with said solid state switching device connected to a second input of said bistable flip-flop circuit, operated in response to an increase in current flowing through said solid state switching device, indicative of saturation of said saturable inductor, to change the state of said bistable flip-flop circuit, said solid state switching device rendered inoperable in response to said bistable flip-flop circuit state change and said energy stored in said saturable inductor discharged and directed by said first and second capacitors to said fluorescent lamp, whereby said fluorescent lamp is operated with periodic discharges from said saturable inductor occurring at a rate capable of maintaining said fluorescent lamp operated.
Claim 2
Dependent Claim
290 words
A high power factor ballast circuit connected between a source of alternating current and a fluorescent lamp, said ballast circuit comprising: a rectifier circuit connected to said power source operated to produce direct current from said alternating current source; a first circuit connection including a power factor correcting saturable inductor and a capacitor connected in series between said rectifier circuit and said fluorescent lamp, said saturable inductor storing energy from said rectifier circuit until saturated; a second circuit connection directly between said fluorescent lamp and said rectifier circuit; a second capacitor connected between said first and second circuit connections; a first solid state switching device connected to a junction between said saturable inductor and said first capacitor and said direct connection, in parallel with said fluorescent lamp; a bistable flip-flop circuit including a first output connected to said solid state switching device; a free running oscillator connected to a first input of said bistable flip-flop circuit; said bistable flip-flop circuit normally operated in response to said free running oscillator to periodically operate said solid state switching device; current sensing means in series with said solid state switching device connected to a second input of said bistable flip-flop circuit, operated in response to an increase in current flowing through said solid state switching device, indicative of saturation of said saturable inductor, to change the state of said bistable flip-flop circuit, said solid state switching device rendered inoperable in response to said bistable flip-flop circuit state change and said energy stored in said saturable inductor discharged and directed by said first and second capacitors to said fluorescent lamp, whereby said fluorescent lamp is operated with periodic discharges from said saturable inductor occurring at a rate capable of maintaining said fluorescent lamp operated.
Claim 3
Dependent Claim
16 words
A ballast circuit as claimed in claim 1 wherein: said rectifier circuit is a bridge rectifier.
Claim 4
Dependent Claim
17 words
A ballast circuit as claimed in claim 2 wherein: said bridge rectifier includes a plurality of diodes.
Claim 5
Dependent Claim
27 words
A ballast circuit as claimed in claim 1 wherein: there is further included a transient filter connected between said source of alternating current and said rectifier circuit.
Claim 6
Dependent Claim
40 words
A ballast circuit as claimed in claim 4 wherein: said transient filter comprises an inductor connected in series between said source of alternating current and said rectifier circuit and a capacitor connected in parallel across said source of alternating current.
Claim 7
Dependent Claim
45 words
A ballast circuit as claimed in claim 1 wherein: said free running oscillator includes a single NOR gate and a variable resistance connected between an output and an input of said gate, said variable resistance operated to control the frequency of operation of said oscillator.
Claim 8
Dependent Claim
18 words
A ballast circuit as claimed in claim 1 wherein: said solid state switching device is a MOSFET transistor.
Claim 9
Dependent Claim
32 words
A ballast circuit as claimed in claim 1 wherein: there is further included a transient protection circuit comprising a resistance and a capacitor in series connected in parallel across said fluorescent lamp.
Claim 10
Dependent Claim
22 words
A ballast circuit as claimed in claim 1 wherein: there is further included preheating means connected in parallel with said fluorescent lamp.
Claim 11
Dependent Claim
15 words
A ballast circuit as claimed in claim 9 wherein: said preheating circuit comprises a capacitor.
Claim 12
Dependent Claim
34 words
A ballast circuit as claimed in claim 1 wherein: there is further included power supply means for said sensing means, said oscillator and said bistable flip-flop connected between said first and second circuit connections.
Claim 13
Dependent Claim
17 words
A ballast circuit as claimed in claim 11 wherein: said power supply consists of a voltage divider.
Claim 14
Dependent Claim
39 words
A ballast circuit as claimed in claim 1 wherein: said current sensing means includes a resistor in series with said solid state switching device and gating means connected between said current sensing resistor and said bistable flip-flop second input.
Claim 15
Dependent Claim
30 words
A ballast circuit as claimed in claim 13 wherein: said bistable flip-flop, said oscillator and said current sensing gating means are all included in a quad NOR gate integrated circuit.
References Cited (Backward Citations)
US4894587A
Cited
US5049790A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-07 | 1996-12-07 | 1997-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-07 | 2000-12-07 | 2001-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-07 | 2004-12-07 | 2005-06-08 | $7700.00 | Window Closed / Lapsed |