| 摘要 |
<p>A PFC converter wherein whether the operation mode is a current continuity mode or a current discontinuity mode, an optimum suppression of harmonics as well as an improvement of power factor can be achieved. There are included: a diode bridge (B1) that rectifies an AC voltage input from an AC input power supply (Vac); a series circuit that includes an inductor (L1) and a switching element (Q1); a rectifying/smoothing circuit that is connected in parallel to the switching element (Q1) and includes a diode (D1) and a smoothing capacitor (C1); and a digital signal processing circuit (13) that on/off controls the switching element (Q1) such that the input current from the AC input power supply (Vac) is similar to the AC voltage thereof. A current detection resistor (R3) is used to detect a current flowing through the inductor (L1) during the off-interval of the switching element (Q1). An operation mode is determined based on the inductor current (IL) flowing at a given timing, and the switching element (Q1) is optimally controlled in accordance with the determined operation mode.</p> |
