US5144205A — Compact fluorescent lamp dimming system

Claim 1

Independent Claim 128 words

A control system for providing electrical power from a source to a gas discharge lamp, comprising: a) a resonant circuit having input and output terminals, said lamp being connectable across said output terminals to provide parallel loading of said resonant circuit; and b) driving means to provide a symmetrical high-frequency ac driving voltage across said input terminals to achieve a resonant response in said resonant circuit and produce a voltage across said output terminals sufficient to strike and maintain an electric discharge in said lamp, said driving means comprising an oscillating circuit including a switching transistor controlled by a regenerative base-drive transformer wherein said driving means after striking said electric discharge drives said resonant circuit at a frequency away from a peak response frequency of said resonant circuit.

Claim 2

Dependent Claim 128 words

A control system for providing electrical power from a source to a gas discharge lamp, comprising: a) a resonant circuit having input and output terminals, said lamp being connectable across said output terminals to provide parallel loading of said resonant circuit; and b) driving means to provide a symmetrical high-frequency ac driving voltage across said input terminals to achieve a resonant response in said resonant circuit and produce a voltage across said output terminals sufficient to strike and maintain an electric discharge in said lamp, said driving means comprising an oscillating circuit including a switching transistor controlled by a regenerative base-drive transformer wherein said driving means after striking said electric discharge drives said resonant circuit at a frequency away from a peak response frequency of said resonant circuit.

Claim 3

Dependent Claim 19 words

The control system of claim 1 wherein said resonant circuit comprises a capacitor and an inductor connected in series.

Claim 4

Dependent Claim 14 words

The control system of claim 2 wherein said lamp is connectable across said capacitor.

Claim 5

Dependent Claim 33 words

The control system of claim 1 wherein said oscillating circuit includes two switching transistors, connected in series, and a regenerative base-drive transformer to alternately provide base drive to each of said switching transistors.

Claim 6

Dependent Claim 36 words

The control system of claim 1, wherein the frequency away from said peak response frequency of said driving voltage is about 37 kHz and said peak response frequency of said resonant circuit is about 40 kHz.

Claim 7

Dependent Claim 21 words

The control system of claim 1 wherein the voltage across said output terminals is approximately between 100 V and 1000 V.

Claim 8

Dependent Claim 132 words

A control system for providing electrical power from a source to a gas discharge lamp, comprising: a) a ballast connected between said source and said lamp to provide a first current at a first frequency from said source to said lamp, substantially determining the power thereto; b) means connected between said source and said lamp, said means having a resonant circuit connected in parallel with said lamp to simultaneously and continuously provide a second current at a second frequency, higher than said first frequency and corresponding to the peak response frequency of said resonant circuit, from said source to said lamp to strike and maintain an electric discharge therein; and c) a first inductor connected between said lamp and said ballast to substantially block said second current from propagating through said ballast.

Claim 9

Dependent Claim 132 words

A control system for providing electrical power from a source to a gas discharge lamp, comprising: a) a ballast connected between said source and said lamp to provide a first current at a first frequency from said source to said lamp, substantially determining the power thereto; b) means connected between said source and said lamp, said means having a resonant circuit connected in parallel with said lamp to simultaneously and continuously provide a second current at a second frequency, higher than said first frequency and corresponding to the peak response frequency of said resonant circuit, from said source to said lamp to strike and maintain an electric discharge therein; and c) a first inductor connected between said lamp and said ballast to substantially block said second current from propagating through said ballast.

Claim 10

Dependent Claim 14 words

The control system of claim 7, wherein said ballast comprises a leakage reactance auto-transformer.

Claim 11

Dependent Claim 19 words

The control of claim 7 wherein said resonant circuit comprises a capacitor and a second inductor connected in series.

Claim 12

Dependent Claim 18 words

The control system of claim 7 wherein said second frequency is approximately between 20 kHz and 50 kHz.

Claim 13

Dependent Claim 19 words

The control system of claim 7 wherein said inductor has an inductance approximately between 20 mH and 100 mH.

Claim 14

Dependent Claim 161 words

A control system for providing electrical power from a source to a gas discharge lamp, comprising: a) a resonant circuit having input and output terminals, said lamp connectable across said output terminals to provide parallel loading of said resonant circuit; b) driving means for providing a high-frequency driving voltage across said input terminals to acheive a resonant response, having a predetermined peak voltage value, in said reasonant circuit and produce a voltage on said output terminals sufficient to strike and maintain an electric discharge in said lamp; c) means connected to said resonant circuit for sensing when said resonant response exceeds said predetermined peak voltage value; and d) means connected to said driving means and responsive to said sensing means for shifting the frequency of said driving voltage away from the peak response frequency of said resonant circuit when said resonant response exceeds said predetemined peak voltage value; whereby the voltage across said output terminals remains below a predetermined maximum value.

Claim 15

Dependent Claim 161 words

A control system for providing electrical power from a source to a gas discharge lamp, comprising: a) a resonant circuit having input and output terminals, said lamp connectable across said output terminals to provide parallel loading of said resonant circuit; b) driving means for providing a high-frequency driving voltage across said input terminals to acheive a resonant response, having a predetermined peak voltage value, in said reasonant circuit and produce a voltage on said output terminals sufficient to strike and maintain an electric discharge in said lamp; c) means connected to said resonant circuit for sensing when said resonant response exceeds said predetermined peak voltage value; and d) means connected to said driving means and responsive to said sensing means for shifting the frequency of said driving voltage away from the peak response frequency of said resonant circuit when said resonant response exceeds said predetemined peak voltage value; whereby the voltage across said output terminals remains below a predetermined maximum value.

Claim 16

Dependent Claim 19 words

The control system of claim 12 wherein said resonant circuit comprises a capacitor and an inductor connected in series.

Claim 17

Dependent Claim 14 words

The control system of claim 13 wherein said lamp is connectable across said capacitor.

Claim 18

Dependent Claim 24 words

The control system of claim 12 wherein said driving means comprises an oscillating circuit including a switching transistor controlled by a regenerative base-drive transformer.

Claim 19

Dependent Claim 21 words

The control system of claim 12 wherein the frequency of said driving voltage is approximately between 20 kHz and 50 kHz.

Claim 20

Dependent Claim 45 words

The control system of claim 12 wherein said said sensing means comprises a resistor in series with said resonant circuit and a transistor having its base connected to a first terminal of said resistor and its emitter connected to a second terminal of said resistor.

Claim 21

Dependent Claim 43 words

The control system of claim 17 wherein said driving means comprises a regenerative base-drive transformer and said frequency shifting means comprises a secondary winding of said transformer connected in series with said transistor to load said driving means when said transistor is conductive.

Claim 22

Dependent Claim 146 words

A control system for providing electrical powers from a source to two gas discharge lamps, comprising: a) a pair of ballasts, each connected between said source and a corresponding one of said lamps, to provide a first current at a first frequency from said source to said lamps in parallel, substantially determining the power thereto; b) a resonant circuit connected between said source and said lamps to simultaneously and continuously provide a second current at a second frequency, higher than said first frequency, from said source to said lamps in series to strike and maintain an electric discharge therein; c) driving means to provide a driving voltage across said resonant circuit sufficient to achieve a resonant response therein; and d) first and second inductors, each connected between one of said lamps and said corresponding ballast, to substantially block said second current from propagating through said ballasts.

Claim 23

Dependent Claim 146 words

A control system for providing electrical powers from a source to two gas discharge lamps, comprising: a) a pair of ballasts, each connected between said source and a corresponding one of said lamps, to provide a first current at a first frequency from said source to said lamps in parallel, substantially determining the power thereto; b) a resonant circuit connected between said source and said lamps to simultaneously and continuously provide a second current at a second frequency, higher than said first frequency, from said source to said lamps in series to strike and maintain an electric discharge therein; c) driving means to provide a driving voltage across said resonant circuit sufficient to achieve a resonant response therein; and d) first and second inductors, each connected between one of said lamps and said corresponding ballast, to substantially block said second current from propagating through said ballasts.

Claim 24

Dependent Claim 13 words

The control system of claim 19 wherein said ballasts comprise leakage reactance auto-transformers.

Claim 25

Dependent Claim 20 words

The control system of claim 19 wherein said resonant circuit comprises a capacitor and a third inductor connected in series.

Claim 26

Dependent Claim 16 words

The control system of claim 21 wherein said lamps are connectable in series across said capacitor.

Claim 27

Dependent Claim 24 words

The control system of claim 19 wherein said driving means comprises an oscillating circuit including a switching transistor controlled by a regenerative base-drive transformer.

Claim 28

Dependent Claim 18 words

The control system of claim 19 wherein said second frequency is approximately between 20 kHz and 50 kHz.

Claim 29

Dependent Claim 23 words

The control system of claim 19 wherein said first and second inductors each have an inductance approximately between 20 mH and 100 mH.

Claim 30

Dependent Claim 17 words

The control system of claim 19 further comprising a capacitor connected between said first and second inductors.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1995-09-01	1996-03-02	1996-09-01	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1999-09-01	2000-03-02	2000-09-01	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2003-09-01	2004-03-02	2004-09-01	$7700.00	Window Closed / Lapsed

Compact fluorescent lamp dimming system

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