| 摘要 |
An electronic ballast for a metal halide lamp is provided to improve a light quality by uniformly maintaining an output of a stabilizer and a lamp irrespective of an input change. An electronic ballast for a metal halide lamp includes a rectifier unit(20), a constant voltage unit(400), a first control unit(500), a constant current unit(600), a second control unit(700), a DC/AC conversion unit(800), and an output unit(900). The rectifier unit generates and converts an input voltage into a DC voltage. The constant voltage unit is coupled to a rectifier unit, and uniformly maintains the DC voltage. The constant current unit is coupled to the constant voltage unit and generates a constant current. The DC/AC conversion unit is coupled to the constant current unit and converts the constant current into an AC power. The output unit outputs the AC voltage converted from the DC/AC conversion unit to a lamp(1000). The first control unit is coupled to the constant voltage unit, and supplies and controls the power to a control circuit. The second control unit is coupled to the constant current unit and the DC/AC conversion unit. The second control unit measures an output voltage of the constant current unit, and has a constant voltage control function for preventing an over-voltage generated by an error of a lamp or a deterioration of a lamp. |
