| 摘要 |
PROBLEM TO BE SOLVED: To prevent rise of terminal voltage of a smoothing capacitor due to an extra energy by controlling the power to be supplied to a load circuit. SOLUTION: A smoothing capacitor C1 is connected between the DC output terminals of a rectifying circuit DB via a diode D11 . The DC voltage of the smoothing capacitor C0 is converted to a high frequency power using the switching elements Q1 , Q2 and is then supplied to a discharge lamp FL. A part of the high frequency power is fed back to the smoothing b capacitor C0 via a capacitor C11 . The power to be supplied to the discharge lamp FL can be controlled by changing the switching frequency of the switching element Q1 , Q2 . Moreover, rice of voltage across the smoothing capacitor C0 can be controlled by operation of an inductor L3 inserted to the charging route to the smoothing capacitor C0 . |
