PSU ideas

Stripe · 6 Apr 2006 at 14:04

hello!

i decided the source of my PCs problems was the PSU so i've decided to replace it. after deciding on a nice Tagan 580watt i realise that it won't actually fit in my case (aspire x-qpack).

so i was wondering if anyone had any suggestions on a small but powerful PSU (enough to power the machine in my sig). the dimensions of my current PSU are (in mm) (WxHxD) 150x86x117 and i need another about that size.

thanks.

vanandjuanunited · 6 Apr 2006 at 14:06

http://forums.overclockers.co.uk/showthread.php?t=17511225&highlight=qpack

Stripe · 6 Apr 2006 at 14:29

thanks for the link.

But I can't see how a normal PSU will fit in there. It might be that my DVD-rw is long (is does extend back beyond its housing) but, taking cabling into account, I might only have about an inch spare between the psu and dvd.

so really, I'm looking for a PSU of around 500w with decent amperage on the 12v rail, up to maybe a depth of 140mm, with the cables coming out from the left (when looking at the side that the cables come from) if possible. that is unless I mod my case so that the DVD writer pokes out the front (or i replace my dvd writer).

any more ideas?

Stripe · 6 Apr 2006 at 14:50

im thinking this one. any comments?

Joe42 · 6 Apr 2006 at 15:41

Problem:

Solved:

As taken from this excellent project log over at bit-tech. Definately worth a read.

Stripe · 6 Apr 2006 at 16:03

cool!

that looks interesting but i doubt I have the skills, tools or time to achieve something like that.

quick PSU question: if a PSU has 2 twelve volt rails at around 17A each, does this mean they can combine to make 34A? I'm looking for at least 25A on the 12V but every unit i look at seems to have 2 rails with low ratings.

Joe42 · 6 Apr 2006 at 16:13

alucks said:
cool!

that looks interesting but i doubt I have the skills, tools or time to achieve something like that.

quick PSU question: if a PSU has 2 twelve volt rails at around 17A each, does this mean they can combine to make 34A? I'm looking for at least 25A on the 12V but every unit i look at seems to have 2 rails with low ratings.

Usually yes, as its difficult to make one supply with an amp rating that high, especially if you're trying to make it efficient. So they now use two or even three and somehow combine them up.

I say usually as i think it was a tagen i saw with a combined/separate switch for the 12v rails. I think it may even be the one in the picture, that red switch.

I'm not sure if some psu's split their cables between each 12v rail?
I remember seeing something about load balancing by moving cables around...

fornowagain · 6 Apr 2006 at 19:53

alucks said:
quick PSU question: if a PSU has 2 twelve volt rails at around 17A each, does this mean they can combine to make 34A? I'm looking for at least 25A on the 12V but every unit i look at seems to have 2 rails with low ratings.

Joe42 said:
Usually yes, as its difficult to make one supply with an amp rating that high, especially if you're trying to make it efficient. So they now use two or even three and somehow combine them up.

Actually no. They don't work like that. You can't just combine the rails. Most 99% of PSU on have one 12v source. The rails are over current limiters with a maximum of 20A/240VA. You can't get more out of the combined rails than goes in. They share the 12v source. With one or the other up to the 20A limit and the remaining for the other. The maximum available is the combined maximum wattage. Take it and divide by 12v for the maximum current.

Try this old thread has some more info.

Joe42 · 7 Apr 2006 at 11:25

So the maximum current for the type R is 30A.
Glad you explained that, as i'm looking for a new psu myself atm.

Since you use the type R as an example, and a lot of people seem to recommend it around here, spcr found it was very noisy and trusted reviews found that it blew up their test bench! Not recomended.