| 摘要 |
PURPOSE: A metal halide discharge lamp lighting device is provided to prevent damages of the lamp and lengthen the useful life of the lamp by achieving improved stability of circuit operation with respect to the high voltage pulse during start. CONSTITUTION: A metal halide discharge lamp lighting device comprises an input unit for receiving an AC power; a leakage and electric shock cutoff unit(52) having a zero current transformer connected to the line of the AC power of the input unit, wherein the zero current transformer monitors the current and voltage input from the input unit and outputs voltages in accordance with the result of the monitoring; a full-wave rectifier unit(53) constituted by a diode bridge circuit, wherein the full-wave rectifier rectifies the voltage input from the input unit; a smoothing circuit unit(54) for smoothing the voltage rectified by the full-wave rectifier unit; a power factor compensation unit for compensating the power factor of the voltage smoothed by the smoothing circuit unit; a consumed power maintaining unit for maintaining the consumed power of the voltage compensated by the power factor compensation unit; a transistor control unit for controlling transistors operating by the voltage adjusted by the consumed power maintaining unit; an output frequency control unit for controlling error of the output frequency when the metal halide lamp operates; and an ignitor circuit for generating high voltage pulses when the metal halide lamp starts its operation.
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