| 摘要 |
<p>A power factor correction circuit comprises first and second ac inputs (I1), (I2) for receiving an ac voltage. A rectifier (104) has first and second rectifier inputs (I3), (I4) each connected to a respective ac input (I1), (I2), and first and second rectifier outputs (05), (06) for outputting a dc voltage. Two capacitor banks (C1), (C2) are connected in series between the rectifier outputs (05), (06). A choke (L1) is connected between ac input (I1) and rectifier input (I3). A bi-directional switch (106) is connected to the rectifier inputs (I3), (I4) and receives a control signal for controlling the switching of the bi-directional switch (106) so as to control the charging and discharging of the choke (Ll) through the rectifier (104). A mid-point between the capacitor banks (C1), (C2) is selectively connectable, or connected, to the ac input (I2) according to the magnitude of the ac voltage.</p> |
