Ac/dc converter with passive power factor correction circuit and method of correcting power factor

A method of correcting power factor with a power factor correction circuit, wherein the power factor correction circuit comprises a first inductor, a second inductor, a first capacitor, a second capacitor, a first diode and a second diode, wherein an end of the first inductor is electrically connected to a positive pole of a DC power supply, and the other end thereof is electrically connected to two series routes which are in parallel to each other, wherein the first capacitor and the second diode are on one of the series route;

• an end of the first capacitor is electrically connected to the first inductor, and the other end thereof is electrically connected to a cathode of the second diode, and an anode of the second diode is electrically connected to a ground terminal of the DC power supply;
• the second inductor and the second capacitor are on the other series route;
• an end of the second inductor is electrically connected to the first inductor, and the other end thereof is electrically connected to an end of the second capacitor, the other end of the second capacitor is electrically connected to the ground terminal of the DC power supply;
• the second capacitor is connected to a loading in parallel;
• an anode of the first diode is electrically connected to a point of the series route between the first capacitor and the cathode of the second diode, and a cathode of the first diode is electrically connected to a point of the series route between the second inductor and the second capacitor;
• the method comprising the steps of:
• A. receiving a direct current (DC) from the DC power supply;
• B. conducting the second diode, and providing energy into the loading from the first capacitor and the DC power supply until the second diode is cut off;
• C. providing energy into the loading from the DC power supply until the first diode is conducted;
• D. charging the first capacitor by the DC power supply, and providing energy into the loading until the first diode is cut off;
• E. providing energy into the loading from the DC power supply until the second diode is conducted;
• and
• F. repeating the steps from the step B to the step E until the DC power supply stops providing the DC.