| 摘要 |
PROBLEM TO BE SOLVED: To simplify the circuit of a switching power supply with a power factor improvement function and, further, prevent a voltage applied to a switching device from being higher than a voltage applied to the switching device of a general switching power supply. SOLUTION: A reactor 5 is connected in series to the primary winding of a transformer and a diode 2 and a capacitor 1 which charge a voltage applied to a switching device 13 in the off-period of the switching device 13 are added to it. Further, an auxiliary winding 4 is added to the transformer so as to have charge stored in the capacitor 1 discharged through the auxiliary winding 4 in the on-period of the switching device 13. Moreover, a diode 3 which prevents a flyback current from being applied to the off-period of the switching device 13 is added. |
