What is PFC?

[wacki]

I saw PFC listed as active on certain power supplies, what does that mean?

 

[RIGorous1]

supposed to be "Power Factor Correction"

 

[RIGorous1]

from extremeoverclocking.com:

"What is the PFC? (Power Factor Correction)

Many loads are highly inductive, such a lightly loaded motors and illumination transformers and ballasts. You may want to correct the power factor by adding parallel capacitors. You can also add series capacitors to "remove" the effect of leakage inductance that limits the output current. (Jim Lux -2002).

Non-PFC offers around 0.5~0.6 PF (Power Frequency), 40%~50% power lost.
Active PFC provides more efficient PF(Power Frequency), 0.95~0.99, it means only 1%~5% power has gone. "

Bottom line is that active-pfc's are more efficient and thus save money I guess.

 

[thorin]

RIGorous1 Is likely correct with 'Power Factor Correction' however there are a huge number of PFC accronyms/abreviations I can think of:

Protection Factor Category
Pulse-Flow Coulometry
Policy Feature Card
Programmable Fieldbus Coupler
Powerbuilder Foundation Class
Prefrontal Cortex
Private First Class
Paid From Credits
Partners For Community
Passenger Facility Charge
Perfluorinated Carbons
Persistent Fetal Circulation
Portable Fuel Cell
Plague Forming Cells
Production Flexibility Contract
Premium Fund Check (Cheque)
Preliminary Flight Certification

Thorin

 

[RIGorous1]

Originally posted by: thorin
RIGorous1 Is likely correct with 'Power Factor Correction' however there are a huge number of PFC accronyms/abreviations I can think of:

Protection Factor Category
Pulse-Flow Coulometry
Policy Feature Card
Programmable Fieldbus Coupler
Powerbuilder Foundation Class
Prefrontal Cortex
Private First Class
Paid From Credits
Partners For Community
Passenger Facility Charge
Perfluorinated Carbons
Persistent Fetal Circulation
Portable Fuel Cell
Plague Forming Cells
Production Flexibility Contract
Premium Fund Check (Cheque)
Preliminary Flight Certification

Thorin

LOL, hahaha. :beer: for you

 

[farscape]

Pretty Freakin' Cool?

 

[Daver369]

Power factor correction is way of making an electric circuit look like a resistor. An "active PFC" uses electronic switches along with an inductor and a control circuit to accomplish this. Your typical computer power supply looks like a big capacitor and draws large slugs of current for only part of a line frequency voltage cycle. This is very inefficient and it creates many harmonics which are spewed onto the AC line. Using an active PFC front end in a power supply hides the capacitor from the AC line and lowers the peak current and dramatically reduces thew harmonics. It makes the ac input current look just like the input voltage which is highly desireable. The end result...lower RMS current, lower harmonics. It is accompished however at the expense of efficiency. The PFC circuit creates its own power losses that add to those of the basic power supply.

 

[suklee]

Private First Class was the first thing that came to mind... 🙂

Oh, and welcome to the forums Daver369!