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So You have maxed out what your atx power supply can handle, what do you do? you go out and buy a bigger supply and what do you do with he old one? toss it in the parts bin. Why not put that old psu to some work and have it help out your new psu with the load.
What you need: 2 atx psu's, some wire, and space in the case (may have to remove the drive bays in the back if you have them)
Setting up your system to run dual psu's is very simple. First thing to do is make sure that both psu's work. Now locate the plugs that hook up to the motherboard on both psu's.
Link wire 15 (black) on both psu's together, line 15 is ground and to run dual psu's you need a common ground.
Link wire 14 (green) on both psu's together, line 14 is the "ps-on" line which turns the psu's on. Now your done with the master psu, the master psu is the supply that plugs into the motherboard.
We have to trick the slave supply that the power is ok since there is no motherboard on it to send that signal. To do that we link line 7 (gray) to line 8 (black).
Always make sure you have a load on both supplies, even just a little floppy drive will do.
Atx psu pin out, note that other supply's may use different wire colors.
Dual ATX psu wiring diagram
Note: this method only allows you to run two psu's in one case as separate units, if you need more current I suggest you use matching power supply's and follow these directions but also link 12v line to 12v line on each psu together, same with the 5 volt lines, this way you will get more current if you need it. basically connect everything pin to pin from each atx socket
So, I had some it right. Just copy/pasted here.
Thanks , now know where I goofed.
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Hi
saw some smart guessing as to why...
yep, its a ton of peripherals...
I was playing with the idea of doing this...
= USB scanner (luckily it has a power supply, so it isn't maxing out the port)
= USB radio
+ USB signal future USB printer/digital device.
+ USB webcam (for the hell of it, to fill four ports...)
= parallel laser
= SCSI card,
= SCSI hard drive,
= SCSI burner,
+ SCSI CDROM (currently not connected)
+ hotrod RAIDcard
+ four 7200rpm IDE drives on hotrod (future raided total of four)
= one ATAPI DVD
= two IDE data disks on mobo controller
+ one zipdrive (currently not connected)
= one floppydrive
= (one free connector for data transferrals, iow, I use this to connect hard disks to)
= three case fans
= athlon 1133 @ 266FSB
= the mobo
= CPU cooler
= soundcard
= some rather souped up AGP card with cooler
= NIC
+ NIC-2
= fax/voice-modem
= three sticks of SDRAM (640 total)
= a crane to lift it
https://discussions.virtualdr.com/
I think this would need better than the 300W I have avail right now.
so I actually disconnected a few things in there
the ones marked with + are those I would like to add or currently have not connected
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hmmm, it could be a better Idea to just not load all that stuff in this one big tower but spread it over two machines and run them networked
(in which case there would be two more ATA100 drives, an atapi-CDROM and atapi burner)
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okay, all of above was the original Idea...
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BUT, I have another ATX case with feeble PSU I would still like to use, even if only to make the mobo and CPU power up, and have two AT-style PSU I rather not throw away...
and that's the real reason I asked.
I'll have to use Bistro's sums to see how far I can go on the options I have.
I'll reread the hints about the wiring.
something ain't clear in my mind.
the wire 7 to 8 thing for example.
SADLY, I do not have any kind of inductive AMP meter https://discussions.virtualdr.com/
but, I can borrow one.
now, you do not run the measurement clipping it over the entire bunch of wires, but measure one wire at the time, is that correct?
I just read the stuff, and followed links...
https://discussions.virtualdr.com/ the pics were not cached in there. https://discussions.virtualdr.com/
I do need a picture of sorts.
My english isn't good enough to do this without pics.
guys/lurkers.
don't attempt this if you needn't do this
I will think thrice before I get the solder-gun out.
(I am no electrician, see.)
but... with good explanations, and good advice, one can at least decide if it would be worth a shot.
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it's only FREE advice!
Kind regards, Jaak
VDR SEARCH
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forgot to mention that the hard disks have dedicated drivecooler fans fitted to them, but that adds only about one (maybe two) watt per drive.
this tower has room for sixteen devices...
four at the back in top
nine in frontside regular hanging bays,
one bay fitted at bottom can hold four, but since I need room for cooling, it maxes at three.
total is theoretical max of sixteen
which means ONe messy bunch of ribbons https://discussions.virtualdr.com/
The more I think about this, the crazier it seems...
but I have had six IDE hard disks hanging in there, plus the SCSI HDD, CDrom & CDRW
and zipdrive...
I did not think it was healthy for the powersupply...
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Jaak,
Colors aside below is the typlical ATX connector pinouts and numbering.
http://www.duxcw.com/faq/ps/psconnshort.gif
Also, found another link discussing what needs to be done.
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[This message has been edited by DrMDJ (edited 08-17-2001).]
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It is a supercomputer. https://discussions.virtualdr.com/
Jaak, the old Delta threads have several lists of periphial power requirements. Will dig them out if you don't already have them. Bistro The Queen of Hearts and Train also have them on file as I recall. https://discussions.virtualdr.com/
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hi
do I read this correct?
Could I use one of them 200Watt AT without needing the solderjob on the ATX?
(since I usually shut everything off by the masterswitch on surgeprotector)
OR, is there danger in this?
(after all, the AT might power up drives before the ATX case-button gets hit, and therefore the mobo would not immediately power up, yet connected devices would...)
would that be detrimental to mobo and controller (mobo) ???????
I currently don't have BIOS set to power on after power failure... I could set it to power up when surgeprotect is switched on, but that may not be wise either.
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so far, it seems the ATX + ATX way might be better?
using the feeble ATX as an extra PSU I would get 18Amp extra on +5V, and 4.2A on 12V
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Ermm, euh,
how can this be?
this feeble thing says
output 145W
+3.3 12A ( gotta be for stuff on mobo)
+5VSB 0.8A (stand by power, on mobo)
+5V 18A
-12V 0.5A (what's that do????)
+12V 4.2A
that calculates to roughly
40W ON +3.3 (far as I can tell, there would be nothing drawing on it... is that healthy? maybe that's what DaComputers is warning us about)
90W ON +5
50W ON +12V
whatever way one adds these up, I get confused.
it just don't add up well.
What's the beef on these numbers?
anyone have an explanation even I can understand?
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it's only FREE advice!
Kind regards, Jaak
[This message has been edited by jtdoom (edited 08-17-2001).]
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Hi All,
I'm back to repeat what I said earlier. Jtdoom hit right at the heart of the problem. The method shown in the link provided with DrMDJ's last message leaves the +3.3 V, -12V and +5 VSB on the second supply running with no load and these supplies are not built to run with no load.
Even worse, as peripherals are added the load on the +5 and +12 is increased the load across the transformer becomes more and more unbalanced. Kinda like everyone standing on one side of the boat, it doesn't take much to tip it over.
Depending on the design of the supply and the components used, it may or may not take the abuse. If it doesn't you could lose a lot more than just a Power Supply or a Motherboard. These supplies NEVER shut off, so think - 4 AM, Smoke, Flame, Fire Dept. ;(
DA
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why the hell do you guys think of these bizarre experiments? it sounds dangerous unsafe and no reason for it.
stay with what you got.
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o4 breathalyzer is a safer lower drunk driving test in some states
http://www.cyberhymnal.org/htm/a/n/anddidtf.htm
i guess im zorro
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dacomputers
Always make sure you have a load on both supplies, even just a little floppy drive will do. From the copy/paste post.
jtdoom
now, you do not run the measurement clipping it over the entire bunch of wires, but measure one wire at the time, is that correct?
Yes, one at a time. Hope for your sake it is digital. I have had some fun reading low amps on a Analog. Probably that ear piercing scream you heard a couple years ago.
I will think thrice before I get the solder-gun out. I see no need for one myself.
But, remember both powersupplies must have some load on them. Even if it means putting a B:\ in to meet that requirement.
But with all the harddisk you have https://discussions.virtualdr.com/ I see no problems.
DrMDJ
Puttting the two links together would make for a good tutorial, I believe.
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Awwwwwwwwww forget all that and pick yourself up one of these, jt..... https://discussions.virtualdr.com/
(Throw in a few Y-extenders and you'll be cookin')
[This message has been edited by bistro (edited 08-17-2001).]
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bistro
That would only give him a couple hundred extra watts is all.
What and with jaak having all that $$, witness he is always buying scsi stuff. https://discussions.virtualdr.com/
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Hi All,
When one joins two supplies, should there be a diode between each output source and the parallel circuit? I'm concerned the current differences of the greater PSU output backfeeding against the lesser output and cause damage to the rectifier circuits. the diode allows current to flow in one direction and blocks reverse current.
Maybe I can whip an design for a crude diode interface block if it sounds feasable.
Thoughts?
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It's either that or it's into the woodchipper
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stev-rey
I believe if one where to follow the directions and use two identical, name brand and size, It would not be a problem as long as both have a load. NO LOAD, yes it would be. Might be a good Idea at that though.
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Bistro, That case compares favorably with the Empire State building does it not. How's it going anyhow?
Hi steppenwolf, The challenge is why and how . Overclocking is the same thing, I suppose.
Good point stev-rey. They have to be isolated. Forgot that.
DA is right about loading the output.The loads have to be big enough to dissapate the heat too.
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Goin' pretty good there, greengoose. https://discussions.virtualdr.com/ I just figured that with all that stuff jtdoom's puttin' in thar, he'll need a super tower with a neato-keeno power supply.
Going to the Blue Ridge Mountains for a week. Should be kinda restful--a nice break. Hopefully I won't have any trees fall on my head....
