Dr. Chen graduated from the University of Illinois, Chicago College of Medicine in 2007. She works in Dallas, TX and specializes in Internal Medicine. Dr. Chen is affiliated with Baylor University Medical Center.
Dr. Chen graduated from the Tufts University School of Medicine in 1998. She works in Escondido, CA and specializes in Dermatology. Dr. Chen is affiliated with Palomar Health Downtown Hospital Campus.
Dr. Chen graduated from the Univ De Sao Paulo, Fac De Med, Sao Paulo, Sp, Brazil in 1991. She works in Kapolei, HI and 1 other location and specializes in Ophthalmology. Dr. Chen is affiliated with Pali Momi Medical Center and Queens Medical Center.
LAC USC Medical Center Internal Medicine 1200 N State St, Los Angeles, CA 90033 3234097556 (phone), 3232263867 (fax)
Education:
Medical School University of Southern California Keck School of Medicine Graduated: 2012
Languages:
English
Description:
Dr. Chen graduated from the University of Southern California Keck School of Medicine in 2012. She works in Los Angeles, CA and specializes in Internal Medicine.
A method of operating a discharge lamp includes modulation of lamp power with a first longitudinal mode frequency to reduce segregation of the vapor phase species within the arc tube. The first longitudinal mode excitation frequency is determined by the acoustic response spectrum observed at an upper region of the arc tube when operated vertically. A frequency in an arc-straightening frequency range may also be added to the input power to straighten and center the arc.
Method Of Operating A Discharge Lamp System And A Discharge Lamp System Using A Combination Radial And Longitudinal Acoustic Mode To Reduce Vertical Segregation
Nancy H. Chen - Salem MA, US Scott J. Butler - North Oxford MA, US Joseph A. Olsen - Gloucester MA, US
Assignee:
Osram Sylvania Inc. - Danvers MA
International Classification:
H05B037/02
US Classification:
315209R, 315291, 315307
Abstract:
A discharge lamp system and method of operating a discharge lamp system in which vertical segregation of vapor phase species is reduced. Lamp power is modulated with an arc-straightening frequency and with a frequency that excites a combination radial plus longitudinal acoustic mode of the lamp. The combination radial plus longitudinal acoustic mode may be a combination first radial mode and nth longitudinal acoustic mode and may be excited with a single power frequency or a swept power frequency range. The two frequencies may be provided at the same time, or separately where the modulation at the arc-straightening frequency is 2 to 16 times longer than a subsequent modulation at the combination radial plus longitudinal acoustic mode.
Dimmable Metal Halide Hid Lamp With Good Color Consistency
Nancy H. Chen - North Andover MA, US Joseph A. Olsen - Gloucester MA, US
Assignee:
Osram Sylvania Inc. - Danvers MA
International Classification:
H01J 17/20 H01J 61/12
US Classification:
313576, 313637, 313643, 313568, 313570
Abstract:
Metal halide lighting with good color during dimming may be obtained. An appropriate balance of commonly used metal halides (NaI, DyI, CeI, CaI, TlI) is dosed in the lamp. No mercury is used. A higher than typical xenon fill pressure from 50 to 500 Kilopascals may be used to help control thermal properties and voltage. If necessary, modulation of the power at acoustic resonance frequencies may be used to straighten and center the arc. Efficient and pleasant white output is obtained. As the power is reduced, the chromaticity either (1) remains fairly constant or (2) drifts acceptably towards warm pinkish colors. Large factors of attenuation in output can be realized. The lumen output was reduced by at least a factor of twenty in one sample as the power was dimmed from 70 to 20 watts.
Control Method And Ballast For Run-Up Of Metal Halide Lamp
Nancy H. Chen - North Andover MA, US Joseph A. Olsen - Gloucester MA, US
Assignee:
OSRAM Sylvania Inc. - Danvers MA
International Classification:
H05B 37/00
US Classification:
315247, 315224, 315308
Abstract:
A method of controlling run-up of a metal halide lamp that has a nominal (full) light output during steady state operation and that has a current limit I, includes a lamp ballast sensing lamp current and voltage and calculating power, and evaluating requested power Pand requested current Ito operate the lamp at the nominal light output during run-up to steady state operation, supplying Ito operate the lamp when I≧I, and supplying Pto operate the lamp when I
Fast Run-Up Of Metal Halide Lamp By Power Modulation At Acoustic Resonance Frequency
Nancy H. Chen - North Andover MA, US Joseph A. Olsen - Gloucester MA, US
Assignee:
OSRAM SYLVANIA Inc. - Danvers MA
International Classification:
H05B 37/02
US Classification:
315224, 315291, 315246, 315209 R, 315DIG 2
Abstract:
A method of controlling run-up of a metal halide lamp that has a nominal (full) light output during steady state operation and that has a current limit I, includes, during run-up of the metal halide lamp to steady state operation, evaluating requested power Pand requested current Ito operate the lamp at the nominal light output Lduring the run-up, supplying Ito operate the lamp so long as I≧Iand supplying Pto operate the lamp when I
Method And Gas Discharge Lamp With Filter To Control Chromaticity Drift During Dimming
Techniques are disclosed that allow for the use of metal halide lamps in dimming applications, as well as other discharge lamps susceptible to dimming-induced chromaticity drift. Examination of such lamps reveals that some of the spectral changes that cause chromaticity drift during dimming are localized in narrow band regions of the spectrum, and lamp emission in these regions is enhanced (either increased or decreased) relative to the rest of the spectrum. Selective filtering of the enhanced emission caused by dimming can be used to reduce chromaticity shift. For instance, a filter deposited on and/or integrated into a lamp component (such as the arc tube, shroud, and/or outer jacket) operates to block transmission of those regions of the spectrum.
Light Output Control Technique By Estimating Lamp Efficacy As A Function Of Temperature And Power
Techniques are disclosed for controlling the light output of a lamp, where lamp efficacy is estimated as a function of estimated lamp temperature and instantaneous input power, or as a function of estimated lamp temperature only. Whether efficacy is estimated as a function of temperature and power, or as a function of temperature only can depend on changes in the lamp operating scenario. The techniques estimate lamp temperature by tracking energy input to and losses from (losses such as radiation, conduction, emission) the lamp arc tube, and determine the corresponding instantaneous light producing ability. The techniques may further be implemented to deliver the appropriate power command to obtain a desired light output. The techniques can be applied towards a general control in which arbitrary or custom light output vs. time paths are produced, and may be implemented by a processor programmed or otherwise configured to execute the desired control scheme.
Metal Halide Lamps With Fast Run-Up And Methods Of Operating The Same
Nancy H. Chen - North Andover MA, US James A. Avallon - Beverly MA, US Edgar G. Estupiñán - Peabody MA, US
Assignee:
OSRAM SYLVANIA INC. - Danvers MA
International Classification:
H05B 41/36 H01J 61/20
US Classification:
315326, 313639
Abstract:
The present disclosure describes metal halide lamps having a discharge vessel, a discharge space, and at least one electrode extending into the discharge vessel in a sealed fashion so as to be in contact with the discharge space. A fill gas, at least one fill material, and optionally at least one volatile material are present in the discharge space. In some cases, the lamps can exhibit at least one of reduced run-up time, increased initial light output, and long life, while remaining useful for general lighting applications. Also described are methods for operating such metal halide lamps.
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