AC-DC power converter

An AC-DC power converter, comprising:

• a) a rectifier bridge and filter configured to convert an external AC voltage to a sine half-wave DC input voltage;
• b) a first energy storage element configured to store energy from said sine half-wave DC input voltage via a first current through a first conductive path during a first operation mode, wherein said first current rises during said first operation mode;
• c) a second energy storage element configured to store energy from a second DC voltage via a second current through a second conductive path during said first operation mode, wherein said second current rises during said first operation mode;
• d) a transistor configured to share said first and second conductive paths;
• e) said first energy storage element being configured to release energy to a third energy storage element and a load through a third conductive path during a second operation mode, wherein said third energy storage element is configured to generate said second DC voltage, and wherein said first current declines during said second operation mode;
• and
• f) said second energy storage element being configured to release energy to said load through a fourth conductive path during said second operation mode, wherein a peak value of said first current is configured to vary along with said sine half-wave DC input voltage, and wherein an output of said AC-DC converter is configured to be substantially constant.