Active PFC

The preferable type of PFC is Active Power Factor Correction (Active PFC) since it provides more efficient power frequency. Because Active PFC uses a circuit to correct power factor, Active PFC is able to generate a theoretical power factor of over 95%. Active Power Factor Correction also markedly diminishes total harmonics, automatically corrects for AC input voltage, and is capable of a full range of input voltage. Since Active PFC is the more complex method of Power Factor Correction, it is more expensive to produce an Active PFC power supply.

Passive PFC

The most common type of PFC is Passive Power Factor Correction (Passive PFC). Passive PFC uses a capacitive filter at the AC input to correct poor power factor. Passive PFC may be affected when environmental vibration occurs. Passive PFC requries that the AC input voltage be set manually. Passive PFC also does not use the full energy potential of the AC line.
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上面說 : 主動式是用複雜的方法來修正95%左右的功率因數
被動式只須在交流電輸入端加個電容器來修正少量的功因!!
(總比沒有修正的好)

繼續調查主動式修正電路是如何構成的!!!