| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve efficiency at light load without increasing a boosting inductor or an output smoothing capacitor by reducing the switching frequency of a PFC power supply to reduce the switching loss at light load and by keeping the switching frequency high at heavy load. <P>SOLUTION: A capacitor C1 is provided in a triangular wave generating circuit 10-3. The triangular wave generating circuit 10-3 outputs triangular waves by charging/discharging the capacitor C1. The charge/discharge of the capacitor is controlled by an output current of an oscillation frequency control circuit 10-2 that is input into a comparator Cmp. <P>COPYRIGHT: (C)2012,JPO&INPIT |
