| 摘要 |
PURPOSE:To obtain an electric-discharge lamp lighting device wherein, even when the switching frequency of a switching element is changed, an input power factor is not lowered and power-supply harmonics are not increased. CONSTITUTION:This device is provided with a charging capacitor 6 which charges an AC voltage AC rectified by a rectifying circuit 1 and with a high-frequency conversion means which converts the DC load of the charging capacitor 6 into a high-frequency at a frequency set by a connected capacitor 16 and which turns on an electric-discharge lamp load 12. In addition, the device is provided with a bridge capacitor 15 which superposes the output of the rectifying circuit 1 on a high-frequency voltage, with a capacitor-capacity-variable means 30 which changes the capacitance of the capacitor 16 setting the frequency of the high frequency output by the high-frequency conversion means and with a capacitor variable and capacitance means 31 which changes the capacitance of the bridge capacitor 15 according to a change in the frequency of the high frequency. |
