| 摘要 |
A circuit arrangement and control thereof for igniting a high intensity discharge lamp, for reducing current stresses imposed on semiconductor devices during a polarity transition of a lamp voltage or lamp current, and for maintaining a parasitic current within an envelope of a square wave lamp current. A high frequency ignition voltage is only applied to the lamp during a starting operation. After the lamp breaks down in the starting operation, an imbalanced high frequency current flows through the lamp to assist a glow-to-arc transition. The high discharge current of the buck filter capacitor that is generally applied to the semiconductor devices during the polarity transition of the lamp voltage or lamp current, due to lamp extinguishing, is reduced. The lamp current is maintained as a low frequency square wave. Any spikes that may occur at the polarity transition of the lamp voltage or lamp current are superimposed on the lamp current within the envelope of the low frequency square wave lamp current.
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