need to build P.S. for 12V 40~50 amps

Discussion in 'The Projects Forum' started by clickergod, Jan 23, 2013.

  1. clickergod

    Thread Starter New Member

    Jan 23, 2013
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    tired of searching
    can anyone point me in the right direction or have a diagram for building a power supply starting with 120Vac dropping to 12Vdc holding 40 to 50 amps for constant use little down time preffer some filtering on imput also

    if its needed its running a car audio system ive been converting atx power supplies but they only last about a month before its blows the rectifier's amp requires 10.5 to 16V at max draw 33A thats why im looking to build up 40A min.


    Any help is apreciated

    Thanks in advance

    Clicker
     
  2. bountyhunter

    Well-Known Member

    Sep 7, 2009
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    strantor likes this.
  3. clickergod

    Thread Starter New Member

    Jan 23, 2013
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  4. clickergod

    Thread Starter New Member

    Jan 23, 2013
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    unless someone has advice on building up an ATX supply to handle higher amperage
    Changint out trans. and rectifiers caps etc
     
  5. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    If you are modifying the ATX supply, you have to use all the wires coming from the 12 Volt line and all of the ground wires. You cannot expect a single 18 guage wire to pass that amperage. Also, you must make sure the bundle of wires in the ATX supplies doesn't interfere with heat exchange/air movement. I regularly use them for for high-current output. You have to be careful not to overload each +12V rail. Parallelling the loads on the two (or more) 12 volt rails doesn't work well either.

    If you really need something that can handle one load of 40 amps or more, you would be better off with a battery charger/battery booster similar to this... It is more than double the price of the ATX supply but it will likely do what you want.

    http://www.ebay.com/itm/IOTA-DLS-45...12564?pt=Battery_Chargers&hash=item3f1b25f714
     
  6. clickergod

    Thread Starter New Member

    Jan 23, 2013
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    im an IT tech i have close to 50 atx supplies laying around right now ive been using them to power car audio inside for last few years .. im usually good with electronic's just anymore my memory fails me

    how hard would it be to desolder resolder in parts on an ATX to put out a higher amperage and not detonate the rectifier on the 12v rail
     
  7. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    For the load you are talking about, the supply most likely is killing itself trying to keep up with the power on transients/large pulsed current requirements.

    Do you have a 1 Farad cap (or more) on the outputs?

    When the rating for the supply is 12V@100A, the power is typically split between 2 or 3 "rails", which can handle around 35 Amps each. You'll need to find a way to combine all of the rails (and grounds) into one wire, so that feedback from 1 rail doesn't disrupt the operation of another rail.
     
  8. BReeves

    Member

    Nov 24, 2012
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    Something like this..
     
  9. clickergod

    Thread Starter New Member

    Jan 23, 2013
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    yeah thats about what i need to do got bored tried setting up something along those lines on a 600W supply with 2 12v rails on a 30 amp draw after about 3 minutes the rectifier did a roman candle effect

    can you recomend a rectifier setup for atx supply that can handle load?
     
  10. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Need One of these, or similar for each rail, feeding a 1F+ cap. Diodes will need a good heatsink on them (An old CPU sink w/fan would work for all 3), hence the TO-247 mountable package.
     
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