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Thread: Active PFC

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    Default Active PFC

    Does APFC always imply one capacitor?

    I have a KDM-M6480 that claims

    "Active PFC 115-230 Volts AC" on the label

    but at the same time it has a voltage selection switch and two primary capacitors.


    Before anyone tells me it is garbage and I should never use this on a computer; I know, and turned it into a voltage supply.

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    Two bulk caps in a Corsair PSU:




    Also, a KDM-M6480 does not have APFC.

    It's garbage.

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    I believe you; so the label lies.
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    It's KDM. Of course the label lies.

    Their website even says that the lower wattage units don't have APFC and that you would need the KDM-P80-PATX6550 550W if you want APFC.

  5. The Following User Says Thank You to Jon Gerow For This Useful Post:

    ashiekh (06-23-2019)

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    Default

    sometimes there are 2 caps primary, but why? is it maybe parallel connected for increase the electric capacity?

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    In the 'old' days it was so they could be connected differently for 110V or 220V (for 110V they were connected to form a voltage double using 2 of the bridge diodes)
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    Quote Originally Posted by Jon Gerow View Post
    ... if you want APFC.

    I'm not so sure I want APFC; given how it may not like some rectangular wave UPS outputs (so called pseudo sine wave)
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    Last edited by ashiekh; 06-23-2019 at 04:25 PM.

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    Quote Originally Posted by ashiekh View Post
    I'm not so sure I want APFC; given how it may not like some rectangular wave UPS outputs (so called pseudo sine wave)
    With a proper PWM controller and/or a high enough voltage bulk cap, it shouldn't matter.

    Weren't we having this conversation in another thread?

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    You are right, I'll try not to cross thread...

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    Quote Originally Posted by psupply View Post
    sometimes there are 2 caps primary, but why? is it maybe parallel connected for increase the electric capacity?
    Simple, 2 reasons:
    a) Size -> 2 smaller ones have a smaller diametre
    b) the Person designing the PCB wanted it that way

    There are some lower wattage PSU with more than one Cap, though they are mostly older -> Cooler Master Real Power PRO is one of them.
    Its mostly used in high wattage PSU though.

    If we're talking about 1000W or more, chances are there is more than one Cap inside.

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