What determines a PSU's wattage?

Discussion in 'Power Supplies' started by Maximilian, Jan 2, 2013.

  1. Maximilian

    Maximilian Lifer

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    For example the seasonic x650 and the x750, what is different internally about the 750 watt model that allows it an extra 100w?
     
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  3. philipma1957

    philipma1957 Golden Member

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    good question maybe jonnyguru has some photos on his reviews.


    here is the platinum 660



    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=326


    here is the platinum 1000


    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=264


    my switching power supply knowledge is not that of my old school

    linear transformer rectifier cap setup.


    I built lots of them for stereo amps pretty simple to make that kind of psu.

    I do not know what the lay out needed is for switching.

    both of these have vrm's that is a voltage regulation module they are not different both are apw7159 but they also use mosfets and the layout looks the same but maybe one can handle more power then the other. I do see he mentions that the 660 watter has 2 GBJ1506 bridge rectifiers and I know that this convert ac to dc. it looks like the rectifiers in the 1000 watter are 6R099 HBH116. I know that these must handle more current. then the ones in the 660 watter. So I am sure about the rectifiers being one reason the 1000 watter is 1000 watts
     
    #2 philipma1957, Jan 2, 2013
    Last edited: Jan 2, 2013
  4. lehtv

    lehtv Elite Member

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    Platinum 660: http://www.jonnyguru.com/modules/NDReviews/images/SeasonicSS660XP/DSCF8508.JPG
    Platinum 1000: http://www.jonnyguru.com/modules/NDReviews/images/SeasonicSS1000XP/DSCF4295.JPG

    Look at the size and number of capacitors.

    Comparing the X650 and X750 in particular, differences are definitely harder to notice...
     
    #3 lehtv, Jan 2, 2013
    Last edited: Jan 2, 2013
  5. Eureka

    Eureka Diamond Member

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    I'd assume higher rated parts, stronger components, things that are suited for holding higher currents. I'm assuming part of it is put in by the manufacturer, such as a current limiter.

    It may very well be that those 650s could handle 750 watt but it's limited by the manufacturer.
     
  6. lehtv

    lehtv Elite Member

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  7. philipma1957

    philipma1957 Golden Member

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    yeah the caps are better in the 1000 watter as it appears to be 3 vs 2.

    Since the rectifiers are different the 1000 watters have to hold more amps. but like you said the 650 and the 750 would be harder to tell apart.
     
  8. Eureka

    Eureka Diamond Member

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    I really wonder if those limits aren't self imposed. Of course all units will be overbuilt and underrated. Still, even at their highest usable rating, the temperatures recorded are still acceptable. There's a part of me that thinks those PSUs can go even higher than that.

    I don't have the resources or experience to actually do it, but I wonder exactly how different the x650 and x750 are internally.
     
  9. philipma1957

    philipma1957 Golden Member

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    you need to directly compare the internals.

    the rectifiers

    the caps

    the mofsets etc
     
  10. Eureka

    Eureka Diamond Member

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    No money no honey. :( If I had unlimited supplies I'd love to dissect both.
     
  11. lehtv

    lehtv Elite Member

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    In JonnyGuru's reviews (x650, x750), the higher wattage unit is less efficient at full load, perhaps that could be interpreted as supporting x650 being more underrated. However, x750 is also less efficient at low loads

    Send JonnyGuru a PM? :D
     
  12. bryanl

    bryanl Golden Member

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    Also larger inductors in higher power units - transformer and output filter chokes.
     
  13. TemjinGold

    TemjinGold Diamond Member

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    Can I interest you in some Diabloteks? ;)
     
  14. Eureka

    Eureka Diamond Member

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    Whoops, I meant to say all reliable units.

    That being said, I do have hope for some of these "unreliable" units. Apevia non-brand 420W power supply. 7 years and going.
     
  15. lehtv

    lehtv Elite Member

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    Sure, but I doubt you've ever run your Apevia unit close to its maximum. I have a prebuilt with some noname unit that's over 10 years old but since it's an office PC with only a Pentium 4 and a Radeon 9600 that's never at load, it still works fine.