Patent EP0386990A2 successfully refreshed from Google Patents.
EP0386990A2
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EP
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Operating method and circuit for discharge lamps
Assignee: General Electric Co
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Filing: 1990-03-06
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Granted: —
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Expires: 2010-03-06
Abstract
Abstract A circuit arrangement for, and a method of, operating a high pressure discharge lamp are disclosed, especially such a lamp which contains a high xenon pressure along with a fill of mercury and a halide typically used for metal halide lamps. The high xenon pressure allows the xenon-metal halide lamp to obtain instantaneous light at a high intensity level which is particularly suited for automotive applications. The circuit related to the present invention provides for acoustic (high frequency) operation of the lamp which substantially eliminates known disadvantages of the high pressure xenon lamp of (1) severe arc bowing of such lamps having electrode spacing greater than two millimeters; (2) increased hot-spot temperatures of such lamps; (3) decreased cold-spot temperatures of said lamps and (4) reduced lamp efficiency and life respectively due to decreased cold spots and increased hot-spot temperatures. The circuit in a preferred embodiment incorporates frequency modulation to broaden the desired operational frequency band of the circuit along with straightening the arc between electrodes of the high-pressure xenon-metal halide lamp.
Inventors
- 👤 Gary Robert Allen
- 👤 Joseph Michael Allison
- 👤 John Martin Davenport
- 👤 Richard Lowell Hansler
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 07:06
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/28; H05B41/288; H05B41/292; H05B41/2928; H05B39/00; H05B39/04; Y; Y02; Y02B; Y02B20/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
174 words
A method of operating a xenon-metal halide lamp comprising the steps of; (a) supplying to said lamp an excitation signal V(t) having a waveform selected from the group comprising approximately sinusoidal, triangular, sawtooth, exponential and composite whose instantaneous power is time-varying at a frequency in a predetermined range, said excitation signal V(t) having parameters in accordance with the representative expression of V(t); V(t) = Vm sin [2*pi*CF*t + (DF/f*sin(2*pi*f*t)] (1) where Vm = peak voltage of the excitation signal; CF = a carrier frequency of an unmodulated signal; DF = a maximum frequency excursion from the carrier frequency; and f = frequency of a modulating signal (b) selecting the excitation signal to have the parameter of; (b1) f starting from a value of about 0 to a range from about (0.01 x CF) to about (0.05 x CF); (b2) DF starting from a value of about 0 to a range from about (0.07 x CF) to about (0.20 x CF); and (b3) CF having a value of about 20 kHz to about 80 kHz.
Claim 2
Independent Claim
174 words
A method of operating a xenon-metal halide lamp comprising the steps of; (a) supplying to said lamp an excitation signal V(t) having a waveform selected from the group comprising approximately sinusoidal, triangular, sawtooth, exponential and composite whose instantaneous power is time-varying at a frequency in a predetermined range, said excitation signal V(t) having parameters in accordance with the representative expression of V(t); V(t) = Vm sin [2*pi*CF*t + (DF/f*sin(2*pi*f*t)] (1) where Vm = peak voltage of the excitation signal; CF = a carrier frequency of an unmodulated signal; DF = a maximum frequency excursion from the carrier frequency; and f = frequency of a modulating signal (b) selecting the excitation signal to have the parameter of; (b1) f starting from a value of about 0 to a range from about (0.01 x CF) to about (0.05 x CF); (b2) DF starting from a value of about 0 to a range from about (0.07 x CF) to about (0.20 x CF); and (b3) CF having a value of about 20 kHz to about 80 kHz.
Claim 3
Dependent Claim
43 words
A method of operating a xenon-metal halide lamp according to claim 1 wherein said parameters are preferably selected so that; f = 0 DF = 0 and CF = has a value in the range of about 20 kHz to about 80 kHz.
Claim 4
Dependent Claim
60 words
A method of operating a xenon-metal halide lamp according to claim 1 wherein such parameters are preferably selected so that; f is the range from about (0.01 x CF) to about (0.05 x CF); DF is the range from about (0.07 x CF) to about (0.20 x CF); and CF is in the range of about 20 to 80 kHz.
Claim 5
Dependent Claim
140 words
An operating circuit for a gaseous discharge lamp comprising; (a) means for developing a first signal serving as unmodulated signal and having a selectable carrier frequency (CF); (b) means for developing a second signal serving as a frequency-modulating signal and having selectable range along with a selectable modulation frequency (f); (c) means for combining said first and second signals to develop an excitation signal which is applied across said gaseous discharge lamp, said excitation signal serving as a frequency-modulated signal and having center, lower and upper frequencies, said lower and upper frequencies being scanned between at a rate equal to the inverse of said modulation frequency, 1/f, said center frequency corresponding to said selectable carrier frequency, and said center and lower frequencies differing by a quantity, - DF, and said center and upper frequencies differing by a quantity + DF.
Claim 6
Dependent Claim
140 words
An operating circuit for a gaseous discharge lamp comprising; (a) means for developing a first signal serving as unmodulated signal and having a selectable carrier frequency (CF); (b) means for developing a second signal serving as a frequency-modulating signal and having selectable range along with a selectable modulation frequency (f); (c) means for combining said first and second signals to develop an excitation signal which is applied across said gaseous discharge lamp, said excitation signal serving as a frequency-modulated signal and having center, lower and upper frequencies, said lower and upper frequencies being scanned between at a rate equal to the inverse of said modulation frequency, 1/f, said center frequency corresponding to said selectable carrier frequency, and said center and lower frequencies differing by a quantity, - DF, and said center and upper frequencies differing by a quantity + DF.
Claim 7
Dependent Claim
31 words
An operating circuit according to claim 4 further comprising; (a) means interposed between said means for developing said excitation signal and said lamp for generating a signal for starting said lamp.
Claim 8
Dependent Claim
37 words
An operating circuit according to claim 5 further comprising: means for supplying current after said starting of said lamp that initially increases in a ramp-like manner, and then decreases in a ramp-like manner after a predetermined time.
Claim 9
Dependent Claim
94 words
An operating circuit according to claim 6 wherein said means of supplying said current comprises: timer means supplying a reference signal having ramp-like features for developing said increasing and then decreasing ramp-like manner current; said timer means having delay means and energy storage means comprising first and second capacitor having selectable values which determine the duration of said delay means and the rate of the ramp-like current, said selectable values being chosen so that the current to said lamp remains relatively unchanged if the source of excitation to the operating circuit is momentarily interrupted.
Claim 10
Dependent Claim
103 words
An operating circuit according to claim 4 wherein said gaseous discharge lamp comprises (a) a fill within said gaseous discharge lamp comprising: (a1) a xenon gas having a cold-pressure in the range of about 2 to about 15 atmospheres; (a11) mercury having an operating pressure in the range of about 5 to about 20 atmospheres; and (a111) a halide compound of an amount in the range from about 1 mg to about 5 mg; and (b) a pair of electrodes respectively located at opposite ends of said envelope and spaced apart from each other by a distance from about 1.5 to about 5.0mm.
Claim 11
Dependent Claim
96 words
A method of operating a xenon-metal halide lamp having electrodes located at opposite ends according to claim 1 comprising the steps of; selecting a first carrier frequency for said excitation signal V(t) so that an arc condition between said electrodes has a bowed shape, said arc condition providing a concentrated light source for developing a first illumination pattern; and selecting a second carrier frequency for said excitation signal V(t) so that an arc condition between said electrodes has a substantially straight shape, said arc condition providing a concentrated light source for developing a second illumination pattern.
References Cited (Backward Citations)
No citation records indexed.
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