Introduction of passive PFC power supply
Passive PFC power supply is consisted of passive components, its PF value is between 70%~80% approximately. The more voltage of power supply, the requirement size of PFC components becomes greater. The input power voltage is required to switch via manual operation. Passive PFC power supply is using a low pass filter to filter the distortion’s high harmonic wave, and only leave the 60 Hz (or 50Hz) basic wave in order to increase the power factor. Passive PFC power supply can only decrease the current wave within the standard and the power factor can not be corrected to 1. This kind of design has the following advantages, simple structure, easy design, low cost, and only require a filter to correct, but will have the following disadvantages, large dimension of filter, heavy and low efficiency resulted from thermal and voltage decrease while current pass through the filter.
Introduction of active PFC power supply
The PF value of Active PFC power supply is over 90 percent. It is even possible to reach 99.99 percent and include the full range special feature. Active PFC power supply can detect the input voltage automatically, supports 110V to 240V alternative current, its dimension and weight is smaller than passive PFC power supply which goes against the traditional view that heavier power supply is better.