Characterization of Discharge Arc Flicker in High-Intensity Discharge Lamps

High-intensity discharge lamps frequently suffer emission disturbances due to the excitation of acoustic resonances. This paper presents experimentally determined light flicker frequencies and arc motion frequencies at different excitation frequencies and modulation depths. Light intensity fluctuation has been detected with a photodiode. Simultaneously, arc motion was recorded with a camera. The frequencies of both methods are in very good agreement. The behavior of the flicker frequency and the arc motion frequency changes significantly near the acoustic eigenfrequency.