Abstract: A digitally controlled active power factor corrected preregulator wherein a rectifier receives an alternating current voltage and generates an alternating line current and corresponding alternating line voltage with an optimum power factor. A power converter receives the alternating line current from the rectifier and converts it to a direct current and corresponding direct current voltage by virtue of a digital controller which adjusts the waveshape of the alternating line current to match the waveshape of the alternating line voltage to minimize line current distortion of the direct current. The digital controller includes a comparator for determining a difference between a reference voltage input and the direct current voltage to generate an error signal that is correlated by a look-up table to generate a correction signal.