Patent ID: 8345456

Claim:
A control system and a power factor correction circuit, comprising: a rectifier bridge for full-wave rectification of an AC power source voltage; a booster circuit including an inductor, a switching element, a rectifying unit, and a capacitor, the booster circuit being connected to an output side of the rectifier bridge, the switching element, or the switching element and the rectifying unit, the booster circuit controlling an input current from the AC power source by an on-off operation to have a sinusoidal waveform; a voltage error amplifier outputting a voltage error signal obtained by amplifying a difference between a DC output voltage or a divided voltage thereof from the booster circuit and a reference voltage; a current command value generating circuit outputting a signal for controlling an AC input current to have a sinusoidal waveform according to the voltage error signal and an output voltage from the rectifier bridge; a comparator comparing a magnitude of an inductor current signal obtained by detecting a current running in the inductor with a magnitude of an output signal from the current command value generating circuit; a timer circuit setting an off-period of the switching element, the off-period being generated in proportion to a peak value or an average value of the output voltage out of the rectifier bridge, or an effective value of the AC power source, the timer circuit comprising a peak holding circuit that conducts peak holding at a maximum of at least a portion of an output voltage of the rectifier bridge and outputs a corresponding peak holding value; and a reset-set type flip-flop circuit that sets an on-timing of the switching element after the off-period set by the timer circuit, and that sets an off-timing of the switching element when the output signal of the comparator detects that the inductor current signal has reached the output signal of the current command value generating circuit.