which is better Active PFC or Passive PFC?

[MACY]

Hello all ,MACY Here
I was looking for power supply unit for my friends computer,but certainly don't know what is the difference between basic Active PFC(Power factor correction) and Passive PFC? kindly help.

[Effren]

All Discharge Lamps, such as Fluorescent Lamps, High Pressure Mercury Vapour Lamps, Sodium Lamps, Metal Halide Lamps, etc., require ballast(chokes) or transformers for their operation. These devices are inductive in nature. When a Discharge Lamp is switched on, it draws Apparent Power from the mains. This Apparent Power has two components; one is the Active Power actually being consumed by the lamp for illuminating it, and the other is the Reactive Power feeding the electromagnetic circuit of the control gear.
Power factor is the ratio of Active Power to the Apparent Power

hope it help you understand what is power factor.

[MACY]

Hi Effren thanks for your response now I understand what is power factor but i still did not understand what is the difference between Active PFC and Passive PFC?.

[Effren]

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.

[MACY]

ya thats means Active PFC is better than Passive PFC. so we should always opt for for Active PFC right. thanks effren

[Effren]

yes I mean it is preferable .