EP0408121A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Circuit arrangement
Assignee: Philips North America LLC
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Filing: 1990-07-05
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Granted: —
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Expires: 2010-07-05
Abstract
Abstract An arrangement for starting and operating a metal halide lamp from a DC voltage source in a short enough time to render such lamps useful in applications in which an excessive delay in operation would be objectionable.
Inventors
- 👤 Robert Alexander Erhardt
- 👤 Stefan Szuba
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 17:29
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/288; H05B41/2881; H05B41/2882; H05B41/2883; H05B41/36; H05B41/38; H05B41/382; H05B41/386; Y; Y02; Y02B; Y02B20/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
142 words
An arrangement for starting and operating a gas discharge lamp by providing power thereto, suitable to be operated from a d.c. power source, said arrangement including an LC circuit having a predetermined resonant frequency to be connected to said lamp, a commutating device connected to said LC circuit and applying voltage to it, said commutating device to be connected to the d.c. power source, low frequency means connected to said commutating device causing said commutating device to switch the voltage it applies to said LC circuit at a low frequency relative to said resonant frequency, and a high frequency means connected to said commutating device causing said commutating device to switch the voltage it applies to said LC circuit at a frequency higher than said resonant frequency which causes said LC circuit to apply high voltage to said lamp to ignite it.
Claim 2
Dependent Claim
142 words
An arrangement for starting and operating a gas discharge lamp by providing power thereto, suitable to be operated from a d.c. power source, said arrangement including an LC circuit having a predetermined resonant frequency to be connected to said lamp, a commutating device connected to said LC circuit and applying voltage to it, said commutating device to be connected to the d.c. power source, low frequency means connected to said commutating device causing said commutating device to switch the voltage it applies to said LC circuit at a low frequency relative to said resonant frequency, and a high frequency means connected to said commutating device causing said commutating device to switch the voltage it applies to said LC circuit at a frequency higher than said resonant frequency which causes said LC circuit to apply high voltage to said lamp to ignite it.
Claim 3
Dependent Claim
33 words
An arrangement as claimed in Claim 1, wherein said high frequency means causes said commutating device to switch the voltage it applies to said LC circuit at a frequency which varies in time.
Claim 4
Dependent Claim
33 words
An arrangement as claimed in Claim 2, wherein said high frequency means causes said commutating device to switch the voltage it applies to said LC circuit at a frequency which decreases in time.
Claim 5
Dependent Claim
61 words
An arrangement as claimed in Claim 3, wherein the high frequency means is provided with means to decrease the frequency with which the voltage is applied to the LC-circuit in a first period with a first rate and in a second period with a second rate, and wherein the first rate of decrease is higher than the second rate of decrease.
Claim 6
Dependent Claim
63 words
An arrangement as claimed in Claim 1 to 4, wherein said LC circuit includes two autotransformers each with a plurality of coils, said autotransformers including a core with two outer legs and an inner leg, wherein the coils of each autotransformer are wrapped around an associated outer leg of said core and wherein the inner leg of said core includes an air gap.
Claim 7
Dependent Claim
57 words
An arrangement according to Claim 5, wherein a sensing coil is wrapped around the core of said autotransformers for sensing the voltage applied across said lamp and for interrupting the high frequency switching of the voltage applied to said LC circuit if said sensing coil senses a predetermined voltage above an expected ignition voltage for said lamp.
Claim 8
Dependent Claim
43 words
An arrangement according to Claim 6, wherein said commutating device is a bridge circuit and wherein the signal from said sensing coil upon sensing said predetermined voltage across said lamp causes said high frequency means to stop applying voltage to said bridge circuit.
Claim 9
Dependent Claim
105 words
An arrangement as claimed in any of Claims 1 to 7, including control circuits having both voltage monitoring means for monitoring the magnitude of the voltage applied by said power source to said commutating device and producing a signal representing that magnitude and current sensing means for sensing the magnitude of the current applied by said power source to said commutating device and producing a signal representing that magnitude, said control circuits being connected to said power source and controlling the power said arrangement can apply to said lamp in accordance with the signals produced by said voltage monitoring means and said current sensing means.
Claim 10
Dependent Claim
93 words
An arrangement as claimed in any of Claims 1 to 8, including control circuits having a voltage monitoring means for sensing the magnitude of the voltage applied by said power source to said commutating device and producing a signal representing that magnitude, said control circuits being connected to said high frequency means and controlling said high frequency means to stop switching said commutating device at said high frequency at the end of the next cycle of said low frequency when said signal from said voltage monitoring means indicates that said lamp has ignited.
Claim 11
Dependent Claim
66 words
An arrangement as claimed in Claim 1 to 9, wherein said commutating means is a bridge circuit and wherein said voltage monitoring means is connected to said bridge circuit to stop it from providing voltage to said LC circuit after the lamp ignites when said signal from said voltage monitoring means indicates that the voltage from said direct current power source is below a predetermined magnitude.
Claim 12
Dependent Claim
51 words
An arrangement as claimed in any of Claims 1 to 10, including control circuits having a capacitance discharge circuit, said control circuits being connected to said power source and controlling the power said arrangement can apply to said lamp in accordance with the decaying signal produced by said capacitance discharge circuit.
Claim 13
Dependent Claim
56 words
An arrangement as claimed in any of Claims 1 to 11, including control circuits responsive to lamp ignition and connected to said high frequency means for controlling said high frequency means to stop switching said commutating device at said high frequency at the end of the next cycle of said low frequency voltage after lamp ignition.
References Cited (Backward Citations)
No citation records indexed.
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