| 摘要 |
The invention relates to a power factor control circuit (10) and to a universal mains power supply (100). The power factor control circuit comprises input nodes (n1, n2) which receive a rectified input voltage being a rectified mains input voltage, and a drive circuit (IC1) which drives a switch (M1). A series arrangement of the switch and an inductor (L1) is arranged between the input nodes. A series arrangement of a rectifier (D1) and an output capacitor (C2) is arranged parallel to the inductor (L1). The rectifier is non-conductive when the switch is closed. The drive circuit drives the switch for generating a substantially sinusoidal current through the switch being substantially synchronized with a sinusoidal voltage of the mains input voltage. Due to the arrangement the output capacitor in the power factor control circuit according to the invention, the output capacitor can only be charged after a first conducting cycle of the switch. An effect of this arrangement is that no inrush current can occur until after the first conducting cycle of the switch which improves the reliability of the power factor control circuit according to the invention.
|
