| 摘要 |
PURPOSE:To prevent the reaching to a resonant point or phase advancing action of a main invertor circuit even abnormality occurs in a drive signal by setting the resonant frequency of driving and undrivable side drive circuits, driving a switching element, higher than the LC resonant frequency of a main invertor circuit. CONSTITUTION:The respective resonant frequencies of the driving and undrivable side drive circuits 10 and 11 of a discharge lamp lighting device are set higher than the LC resonant frequency of a main invertor circuit 9. If abnormality occurs in a drive signal to an FET 5, the resonant frequency f0 (b) of the circuit 10 is higher than the resonant frequency f0 (a) of the circuit 9 to saturate a winding 12 sooner than the circuit 9 side. Since the resonant frequency f0 (b) of the circuit 10 is higher than the resonant frequency f0 (c) of the circuit 11, the winding 12 side of the circuit 10 is saturated sooner even abnormality occures in the drive signal to make the drive signal of a FET 6 unoccurring, consequently preventing the occurrence of the condition where the FET 5 and 6 are concurrently turned ON. |
