| 摘要 |
PROBLEM TO BE SOLVED: To improve a power factor with a simplified circuit structure by providing a switching circuit for controlling ON and OFF conditions of the connection between the connecting point of the first and second capacitors and one of the inputs forming a pair of the rectifying circuits. SOLUTION: When a switching element 15 is in the On state, a current flows into an inductor from a rectifying circuit. In this case, a peak of the output current is limited to improve a power factor of input current with harmonics suppressing inductors 12a, 12b to reduce the power supply harmonics. Moreover, connection between the connecting point of the first and second input side capacitors 13a, 13b and one of the AC input connecting points of the rectifiers 11 can be switched freely to the rectifying system of the full-wave rectifying and the double voltage rectifying by the switch means 14. When an AC input is 100V system, the switching means 14 is turned ON for double voltage rectifying and it is 200V system, the means 14 is turned OFF for full-wave rectifying. As a result, power factor of input current can be improved and power supply harmonics can be reduced. |
