external power supply for atx Motherboard

[bugs]

Hi all,

I am new here so bear with me, I am thinking of building a mini PC except using a full ATX motherboard. My question is, is it possible to power it using some kind of external power supply like a laptop power supply.

Sorry if this sounds a little silly but i`m not sure if I can do it or if it actually needs an internal PSU

Thanx

Craig Dunn

 

[Nigel Goodwin]

It needs a number of different voltage supplies, as a minimum +5V, +12V and -12V - a laptop supply is only one voltage, and uses switchmode inside to generate the rest it needs.

 

[bugs]

what is the difference between switching and none switching (Sorry if that sounds thick) does anyone have any thoughts on how you could achieve an external power supply for an ATX motherboard

 

[eblc1388]

what is the difference between switching and none switching (Sorry if that sounds thick) does anyone have any thoughts on how you could achieve an external power supply for an ATX motherboard

Buy an proper ATX power supply and places it externally, perhaps also extending the supply output leads using special extension leads(I saw these for sale somewhere but there is never a need to use one).

 

[justDIY]

an external supply would require a LOT of wires to pass through the case some how ... you'd either have bundle them, and they'd become stiff and inflexible, or end up with an ugly spaghetti mass entering the case.

why would you want an external power supply anyway, I can't see any advantage.

alternately, if it's just a board you want to power, get a car-pc power supply. they are tiny switchers (usually 100 watts or so) that fit right into the ATX socket. then you use an external 12v supply to run them. don't expect to run much of a desktop system off only 100 watts.

 

[bugs]

the reason im doing it is I want to make a small media centre pc thing (whatever they are called) and I am a scrooge and have loads of older ATX boards so id like to utilize them but make it as small as possible I>E> the size of the motherboard and thats it

 

[Styx]

the reason im doing it is I want to make a small media centre pc thing (whatever they are called) and I am a scrooge and have loads of older ATX boards so id like to utilize them but make it as small as possible I>E> the size of the motherboard and thats it

since you are going for a media-PC there wont be alot of power-hungry componets (silly GFX card...) there are ATX-compatable very small PSU boards that are perfect for this

and a switching power supply basically is a power supply that takes a higher voltage and "chops" it with the ON/OFF action of a FET to reduce the average.
(you can boost as well, but thats another story)
Switching PSU can be quite efficient 90% at their design load-point, while the alternative is either linear (lossy) or lots of dedicated transformer winding for each of the rails