| 摘要 |
PURPOSE: An electronic ballast for a metal halide lamp is provided to stably operate a lamp by driving a bridge rectifier with a voltage multiplication rectifying circuit and a full-wave rectification circuit. CONSTITUTION: A power supply unit(10) comprises a rectifier(14) rectifying a commercial AC source to a direct current. A power factor control portion(20) outputs the rectified direct current to a DC current of a certain level. An inverter(31) includes a high frequency transformer, pair of switching elements, and a charging/discharging condenser. A choke transformer(32) converts the AC current from the inverter into a voltage controlled DC current. A bridge rectifying unit(34) is connected between the connecting points between two condensers. A voltage multiplication conversion circuit(35) operates the bridge rectifying unit with a voltage multiplication rectifying circuit and a full-wave rectification circuit. |
