| 摘要 |
PURPOSE:To improve input power factor and lower the withstand voltage and the cost by connecting a specified voltage smoothing means and a specified lighting circuit to a rectifier and a boosting chopper circuit connected with an A.C. power supply And their output terminals respectively. CONSTITUTION:Voltage V0 obtained by rectifying A.C. power supply Vs and boosted by a boosting chopper circuit 3 is divided by a voltage smoothing means composed of a first capacitor C1, a diode D, and a second capacitor C2 connected in series and D.C. voltage V1, V2 obtained by each capacitor C1, C2 is supplied to lighting circuits 1, 2, respectively. A lamp DL connected with the secondary side of a transformer T is lighted by operating the circuits 1, 2 provided with at least a current limiting element and a switching element. Since voltage V1, V2 obtained by dividing the high voltage V0 is applied to each element of the circuits 1, 2, the withstand voltage of each element can be lowered. |
