Active PFC Question

[Slaimus]

I understand that active PFC makes the harmonics about the same after passing through the PSU, but why does it also give it auto 115/230V switching? The two seems completely unrelated.

 

[Navid]

Power factor correction has to do with the phase angle between the line voltage and the load current. Correcting the power factor means bringing the two in phase to minimize the reactive power which is not productive.

I don't believe PFC has anything to do with auto 115/230V.

 

[Slaimus]

That was my original question. All active PFC power supplies have auto 115/230V, which seems completely unrelated.

 

[Navid]

Originally posted by: Slaimus
That was my original question. All active PFC power supplies have auto 115/230V, which seems completely unrelated.

I attempted (perhaps unsuccessfully) to answer your question. May be every PSU with active PFC also has auto line voltage ranging (I don't know). But, the auto ranging is not the result of the active PFC.

 

[Zepper]

Actually since the aPFC circuitry mostly resides on the AC side of the PSU, perhaps it is just convenient to add autoranging at the same time as you have to add an AC-side PCB anyway.
.bh.

 

[harrkev]

My guess...

Good PFC raises the cost of the power supply, so it is generally done on the higher quality units. Higher quality units are more likely to handle multiple voltages, because they are not trying to shave every penny.

 

[TopNurse]

If you are interested you can go to http://www.picoelectronics.com as they seem to make a lot of PFC modules. I think every module they make has autoranging AC capability. Perhaps this is because military organizations were the first to want PFC as it makes less problems when you are out and about on some one else's soil.