| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power factor improvement circuit capable of diffusing generating noises and composed of an efficient and simple configuration. <P>SOLUTION: The power factor improvement circuit includes: a rectifier 3 for rectifying an AC voltage of an AC power supply 1; a first series circuit connected to the output of the rectifier in parallel and formed by connecting a step-up reactor L1 and a switching element Q0 in series; a second series circuit connected to the switching element in parallel and formed by connecting a rectifying diode D1 and a smooth capacitor C2 in series; an oscillation circuit 12 for generating a clock signal CLK having a prescribed oscillation frequency; and a control circuit 10 for generating a driving signal in order to drive the switching element in cycles of the clock signal generated by the oscillation circuit and according to a voltage value of the smooth capacitor. In the oscillation circuit, the prescribed frequency is changed according to the driving signal of the switching element. <P>COPYRIGHT: (C)2009,JPO&INPIT |
