Power factor correction (PFC) is the capacity of generating or absorbing the reactive power produced by a load. Power quality issues and regulations require rectifier loads connected to the utility to achieve high power factor. The resistor emulation of the PFC rectifier is carried out by the DC/DC converter. The input to the DC/DC converter is a fully rectified sinusoidal voltage waveform. A constant DC voltage is maintained at the output of the PFC rectifier. A simple method to improve the power factor is to use a tapped transformer. DC motor variable speed control drive-systems are widely used in industrial applications. Some applications require the DC motor running at lower speed. If the DC motors are supplied by AC/DC rectifiers, the lower speed corresponds to lower armature voltage. In power electronic equipments, the PFC circuits are usually added between the bridge rectifier and the loads to eliminate high harmonics distortion of the line current.