A
power factor correction converter capable of fast adjusting load functions to (a) convert a single-phase AC
voltage into a
DC voltage output; (b) control an input current and an input
voltage for a correspondent electrical phase, namely the
power factor that is 1; and (c) control a DC output
voltage level. The converter is provided with a booster-based AC-
DC converter as a core, in which the circuit includes a rectification circuit, a switching circuit consisting of a DC
inductor and a power
crystal, an energy-saving
capacitor, a protection circuit, a
microprocessor, and auxiliary circuits around. The
power factor control, output voltage, and current control and filter modules function in the form of
software program instead of conventional
hardware circuits. Further, a powerful controller uses an output current feedback to enhance the DC output voltage to suppress the disturbance of load.