Patent ID: 8780597

Claim:
An AC-to-DC conversion apparatus, comprising: a first switch-element; an output capacitor; and a bridgeless power factor correction (PFC) circuit, wherein the bridgeless PFC circuit comprising: a bridge circuit comprising second to fifth switch-elements, wherein the second and the third switch-elements are connected in series to faun a first series branch, the fourth and the fifth switch-element are connected in series to form a second series branch, and the first series branch and the second series branch are connected in parallel; a first inductor, having a first terminal connected to a first terminal of an AC input and a second terminal connected to a common node between the second and the third switch-elements; and a second inductor, having a first terminal connected to a second terminal of the AC input and a second terminal connected to a common node between the fourth and the fifth switch-elements, wherein a first group of switch-elements comprise the second and the fourth switch-elements, and are implemented by controllable switch-elements or diodes, wherein a second group of switch-elements comprise the third and the fifth switch-elements, and are implemented by controllable switch-elements or diodes, wherein at least one of the first group of switch-elements and the second group of switch-elements are implemented by controllable switch-elements, wherein a first terminal of the first switch-element is connected to one of a common node between the second and the fourth switch-elements and a common node between the third and the fifth switch-elements, wherein a second terminal of the first switch-element is connected to a first terminal of the output capacitor, wherein a second terminal of the output capacitor is connected to the remaining one of the common node between the second and the fourth switch-elements and the common node between the third and the fifth switch-elements, wherein when the first terminal of the first switch-element is connected to the common node between the second and the fourth switch-elements, a switching of the fourth switch-element is complementary to that of the first switch-element in a positive half cycle of the AC input, and a switching of the second switch-element is complementary to that of the first switch-element in a negative half cycle of the AC input, wherein when the first terminal of the first switch-element is connected to the common node between the third and the fifth switch-elements, a switching of the fifth switch-element is complementary to that of the first switch-element in the positive half cycle of the AC input, and a switching of the third switch-element is complementary to that of the first switch-element in the negative half cycle of the AC input.