@newsgroup: "Hi,
Over the years, I've kept a few ATX power supply from old computers.  Now, 
I'm thinking about upgrading my computer and add more hard disks.  The 
problem is the current power supply might not be able to support so many 
hard disks running at the same time.  Instead of buying a new, more powerful 
power supply, I am planning to use one old piece (350w) to serve the 
motherboard, CD, and 3 hard disks, then another power supply (350w too) to 
serve 3 to 4 more hard disks.  All components are connected to the same 
motherboard.  I need to know how I could turn on both power supply with a 
single press of the power button on the case.  Anyone has any ideas?
Thanks. "
    @newsgroup: "I'm sorry.  I don't quite get it.  Only one power supply can plug to the 
motherboard, how can I jam the wires together so that the second power 
supply receive the power-on signal when I press the button?  I was thinking 
about the Power-On (Green), Power-Good (Gray) and 5 VSB (Purple) wires.  In 
other words, the second power supply would only support the hard disks and 
nothing else, but I need them to be powered up at the same time other 
hardware are up (and down when it's shut down).
"ehsjr" <email_address> wrote in message 
news:5LpVf.443$<email_address>
<quote>"
    @me9: "<quote>
 > I'm sorry.  I don't quite get it.  Only one power supply can plug to
 > the  motherboard, how can I jam the wires together so that the second
 > power supply receive the power-on signal when I press the button?  I
 > was thinking  about the Power-On (Green), Power-Good (Gray) and 5 VSB
 > (Purple) wires.  In  other words, the second power supply would only
 > support the hard disks and  nothing else, but I need them to be
 > powered up at the same time other  hardware are up (and down when it's
 > shut down).
(Top posting corrected to establish a readable thread)
You plug one supply into the motherboard. It will start with the normal 
power on button. You plug one supply into the drives. It simply needs 
the power-on (green) and any ground (black) wire of its (otherwise 
unused mobo connector) to be joined together.
The first problem is connecting to them. You can cut them and use a 
"chocolate block" connector. You can use car-type connectors used to tap 
off wires for things like trailer lights. They are quick and easy to 
use. You can use a socket off an old mobo, after desoldering and 
removing it carefully. Loads of ways of connecting to it, I am sure that 
you will think of something.
Next is, how to connect them together. As suggested, vou can replace the 
power on switch with one with two sets of terminals, or use the reset 
button as a second power on switch. Or you can take one of the existing 
hard drive connectors, from the power supply used to power the mobo, and 
connect a relay (12v or 5 v, your choice) to it and use the relay 
contacts to short the wires together. Or you can use a USB
port on the mobo to do the same thing. Or you can glue a light piece of 
plastic sheet to the lever of a microswitch, stick it in the airflow of 
a mobo fan and use the change in airflow to short the wires together. Or 
ue a sound-operated switch and shout, "Start" at it.. zillions of ways 
that you can detect one supply has started up and use that to short two 
wires together. I am sure that you will think of something..
The points made by other posters about the advisability of using old 
supplies and the remote possibility that you might not load it enough to 
achieve reliable operation are very valid.
I do use two supplies, now and again, though.
I get two identical mini-tower cases and bolt them together side by 
side. I run the file storage hard drives in one case, from their own 
(new) power supply and the mobo + optical drives + system hard drives in 
the other case, from their own (new) power supply. It is much cheaper 
than buying a server case and power supply.
  Air flow and cooling is much easier to arrange - although I typically 
NC mill my own heat transfer devices and stick the pump and reservoir in 
the mobo space of the second case, with the radiator on the back of the 
second case (needs no access for connectors or cards). A liquid cooled 
heatsink on each drive means that I can mount drives top to bottom in 
the second case.
Currently Seagate 300GByte drives are my favourites, with an additional 
hardware RAID controller you can run a TByte, mirrored, no problem. With 
freenas, it makes a nice little, not very expensive, addition to a network.
No way would I do this using old power supplies of dubious parentage for 
anything like that.
Sue"
    @sqlit: ""lee" <email_address> wrote in message news:<email_address>
<quote>
powerful
This is wrong in so many ways.  First and foremost you have two different
potential inside the case. Electronics as a general rule do not like
differences in potentials.
The motherboard is on one potential and the hard drive is on another....
POUF goes the magic.
Let us know how long it works for ya.  I bet it crashes in less than a week."
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