Tilted Forum Project Discussion Community - How important is PFC in choosing a power supply?

Quote:

Power Factor Correction (PFC) allows power distribution to operate at its maximum efficiency. There are two types of PFC, Active PFC and Passive PFC. All of our power supplies are either Active PFC Power Supplies or Passive PFC Power Supplies.

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 requires that the AC input voltage be set manually. Passive PFC also does not use the full energy potential of the AC line.

Non-PFC

Non-PFC power supplies are no longer recommended. In fact, in Europe, power supplies are now required to have either active power factor correction or passive power factor correction.

This was taken from http://www.endpcnoise.com/cgi-bin/e/pfc.html