This is compact power factor controller circuit. It stabilizes device’s electrical demand to give best power factor characteristic of many types of loads. In many application, a direct rectification of the AC line followed by bulk capacitor filtering is used to get the high DC voltage. This capacitor filtering will produce a poor power factor and current spike that distort the power line sine waveform and resulting in the real power that is much lower than an apparent input power. To solve this problem, we can insert a pre-regulation between the bulk capacitor and the rectifier. Here is the circuit:
This power factor controller uses IEC1000–3–2 standard that is a low–cost system solution for boost mode follower. It includes protection against undervoltage, overvoltage, overcurrent, and an inrush current detection. Smaller inductor and MOSFET can be used for follower boost mode to reduce system cost. [Circuit schematic source: ON Semiconductor Application Notes]
