Two power supplies in one case ??
Kenmo
I have 4 really power hungry scsi drives, an scsi zip drive, one 6.4gb ATA33
hd, and one ide cd-rw and ide cd reader. Plus two voodoo2's in sli and a
TNT2.
I have a full tower case.
I need power !!
Thanks
@split.crosig.hr Iveky
first one use for mobo and additional use to supply discs
do you have room in your case or will you hold it outside of case?
"Kenmo" <ke...@gov.ns.ca> wrote in message
news:nORO5.8$Y%3.6...@sapphire.mtt.net...
Kenmo
I guess the mobo leads on the 2nd ps should be taped over in case they short
on the cases sheet metal or chassis.
Any websites on designing one of these beasts ?
Iveky > wrote in message <8ugq5h$6ih6$1...@as121.tel.hr>...
@split.crosig.hr Iveky
another one for HD's and other stuff
ground (black wires) between those 2 power's is always ok cos it is metal
chasis which is also grounded (until chassis is grounded for both power's)
:-)
"Kenmo" <ke...@gov.ns.ca> wrote in message
news:KWSO5.19$Y%3.9...@sapphire.mtt.net...
Kenmo
Are you saying the black mobo cables on the 2nd power supply should be
grounded on the case ???
Thanks
Mike Uchima
mobo connector, to supply the "power on" signal to the second power
supply. This is the signal that tells the power supply to turn on when
you push the power button. Otherwise, the second supply won't turn on.
I don't know the exact details; maybe someone can point you at a Web
site or something. Basically, I think you will need to bridge the
"power on" wires (and maybe the grounds too?) from the mobo connectors
on the two power supplies together... but don't quote me on that.
--
== Mike Uchima == uch...@pobox.com ==
Kenmo
Eric
> Can this be done ?
>
> I have 4 really power hungry scsi drives, an scsi zip drive, one 6.4gb ATA33
> hd, and one ide cd-rw and ide cd reader. Plus two voodoo2's in sli and a
> TNT2.
>
> I have a full tower case.
>
> I need power !!
Why not use just one 600w power supply?
EK
Chris
connectors. You will end up with two power switches, which will mean either
having to turn the drives on and then the system, or alternatively you could
wire up a relay in between the power switch and the psu to activate the
second power supply.
Whilst we're on the topic, I'm thinking of wiring up a pair of ATX supplies
for a monstrous Athlon o/c project. I had thought of making a y-cable to
connect the two psu's to the motherboard (I want a lot of current in
reserve!). That way both psu's would receive the "power-on" signal & be
able to supply power to the board. Anyone know if this would be okay? And
where could I get a couple of sockets like the connector on the board
(Maplin's in the UK say NO!)
--
Chris
----------------------------------------------------
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"Kenmo" <ke...@gov.ns.ca> wrote in message
news:TxUO5.35$Y%3.1...@sapphire.mtt.net...
B
Don't parallel the power supplies. Divide the load ( approximately in
two halves). Put half minus one or two drives on one PSU and the
remainder on the other. Put the mother board on the PSU with less
drives. I don't have the connection data for the power on function but
you should find it easily with some searching. I did a quick search
for you and got to
http://www.pcguide.com/ref/power/sup/parts_Selector.htm Where you
should find the connection to start the "non mother board PSU" (14
Green but confirm this)
You may need to put some extra load on the 5 volt rail to enable the
regulator to be in the correct operating range. Measure both the 5 and
12 volt rails as soon as possible after connecting load or better still
measure them with a dummy load before connecting expensive components.
Good luck
B
"Chris" <Chris.Iso...@btinternet.com> wrote in message
news:8uhqh8$177$5...@neptunium.btinternet.com...
Ken Morris Jr
and which is 12 ?
Thanks
jim dorey
jim dorey
board and drives, poof!!!! but if you were to connect the psu's to load
sensors you could add a regulator after the sensor, then they would share
the load, and if one failed the other would take over and alarm to tell you
that one has failed, the output would be the same as one, but would be less
prone to goin splotz.
B
Scroll down the page and you will see the colours of the wires and the
pinning of the connectors for all the power supply out-puts.
Good Luck
B
"Ken Morris Jr" <ke...@hfx.andara.com> wrote in message
news:3A0CD763...@hfx.andara.com...
Kurt
Just how power hungry are these drives?
I have a mean case, (1) 10k scsi, (3) 7200 rpm scsis, (3) 5400 rpm
scsis, (1) scsi CD-ROM, TNT2, 6 fans counting Everything, etc.
I run them all off a PC Power & Cooling AT 230watt ps.
Never a problem.
Dunno what your dual sli setup pulls tho.
Here's a 450watt ATX:
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=496497090
Kurt
--
Remove "spamless" to email me.
The spam was just getting overwhelming.
I had to...
Eric
> Too easy I suppose.
> Just how power hungry are these drives?
> I have a mean case, (1) 10k scsi, (3) 7200 rpm scsis, (3) 5400 rpm
> scsis, (1) scsi CD-ROM, TNT2, 6 fans counting Everything, etc.
> I run them all off a PC Power & Cooling AT 230watt ps.
> Never a problem.
>
> Dunno what your dual sli setup pulls tho.
> Here's a 450watt ATX:
You mean a 431 watt ATX.
Kurt
See what you mean.
Not my auction, I just went by the title without reading the specs.
Sorry to short you 19 watts - that's 2 more drives sequentially
booting!
I'm so ashamed....
Eric
> >> Dunno what your dual sli setup pulls tho.
> >> Here's a 450watt ATX:
> >
> >You mean a 431 watt ATX.
> See what you mean.
> Not my auction, I just went by the title without reading the specs.
> Sorry to short you 19 watts - that's 2 more drives sequentially
> booting!
>
> I'm so ashamed....
In Japan, executives dive out of the 19th story window for less. <g>
Total watts fudging is rampant in the power supply industry.
Franc Zabkar
<Chris.Iso...@btinternet.com> put finger to keyboard and
composed:
>If they are AT then all you should need to do is tape up the m/board
>connectors. You will end up with two power switches, which will mean either
>having to turn the drives on and then the system, or alternatively you could
>wire up a relay in between the power switch and the psu to activate the
>second power supply.
Connect the AC output of the first P/S to the AC input of the second.
Wire the second P/S so that its power switch is always on. Connect the
monitor to the AC output of the second P/S.
You can now control both supplies via the on/off switch of the first.
-- Franc Zabkar
Please remove one 'e' from my address when replying by email.
Chris
news:3a107198...@news.ozemail.com.au...
That is *so* neat! Thanks for the idea!
Eric
> > Connect the AC output of the first P/S to the AC input of the second.
> > Wire the second P/S so that its power switch is always on. Connect the
> > monitor to the AC output of the second P/S.
> >
> > You can now control both supplies via the on/off switch of the first.
>
> That is *so* neat! Thanks for the idea!
Just make sure that a) the rating of the AC outlet of the first supply
is higher than the power used by the second supply and monitor, and
b) that the on/off switch can handle the current for both supplies and
the monitor.
Watson A.Name
>
> If they are AT then all you should need to do is tape up the m/board
> connectors. You will end up with two power switches, which will mean either
> having to turn the drives on and then the system, or alternatively you could
> wire up a relay in between the power switch and the psu to activate the
> second power supply.
>
> for a monstrous Athlon o/c project. I had thought of making a y-cable to
> connect the two psu's to the motherboard (I want a lot of current in
> reserve!). That way both psu's would receive the "power-on" signal & be
> able to supply power to the board. Anyone know if this would be okay? And
> where could I get a couple of sockets like the connector on the board
> (Maplin's in the UK say NO!)
>
> Chris
>
> ----------------------------------------------------
> Remove SPAM to reply by e-mail
>
> news:TxUO5.35$Y%3.1...@sapphire.mtt.net...
> > These will be AT ps.
> >
> > Thanks
> >
> > Mike Uchima wrote in message <3A0C11...@pobox.com>...
> > >If these are ATX supplies, you will need to do a little wiring on the
> > >mobo connector, to supply the "power on" signal to the second power
> > >supply. This is the signal that tells the power supply to turn on when
> > >you push the power button. Otherwise, the second supply won't turn on.
> > >
> > >I don't know the exact details; maybe someone can point you at a Web
> > >site or something. Basically, I think you will need to bridge the
> > >"power on" wires (and maybe the grounds too?) from the mobo connectors
> > >on the two power supplies together... but don't quote me on that.
A couple of important points:
First off, a PC SMPS (switch mode power supply) will not operate with no
load on it. Generally the +5V supply must have an amp or more current
drawn, and if it doesn't then it can't regulate the supply at 5V and the
overvoltage will kick in and the whole PS will shut down. So if you use
one SMPS to power only the peripherals - some periphs use only +12V -
and they don't draw any/enough current from the +5V, then it will
probably shut down.
Second: If you try to parallel two power supplies, then you have to
keep them isolated with high current diodes. If you connect the outputs
of two SMPSes directly together, then they will fight one another to try
to control what each thinks is +5V, and they could do any of a number of
strange things including shutting down.
If you use a pair of diodes to isolate the two SMPSes, then the diodes
will have some voltage drop depending on the current. If you use
Schottky diodes, then the voltage drop will be around 2/5 to 1/2 volt.
The voltage supplied to the motherboard will then be only about 4.5V,
and this will not be enough. So you have to change the output of the
SMPSes to add about a half volt so they put out about 5.5V before the
diodes, and between 4.75V and 5.25V after.
And this doesn't take into account the problem that one supply may put
out a fraction of a volt more than the other, and thus will supply most
or all the current, while the lower voltage supply supplies almost
none. So the two SMPSes have to be adjusted to share equally in
supplying current.
You're probably looking at this and saying, gee, this is getting too
complicated. Well, yeah, that's right. It's not just simply twisting
some wires together.
Watson A.Name
>
> Thanks for your reply. A silly question perhaps, but which rail is 5 volts
> and which is 12 ?
>
> Thanks
You just stick your DMM's red test lead probe into either with the DMM
set to 20V or so range, and it immediately becomes obvious which is
which. One will read about 5VDC or else about 12VDc. The black test
lead goes to ground.
> B wrote:
[snip]
Watson A.Name
>
> Chris wrote:
>
> > > Connect the AC output of the first P/S to the AC input of the second.
> > > Wire the second P/S so that its power switch is always on. Connect the
> > > monitor to the AC output of the second P/S.
> > >
> > > You can now control both supplies via the on/off switch of the first.
> >
>
> is higher than the power used by the second supply and monitor, and
> b) that the on/off switch can handle the current for both supplies and
> the monitor.
You make an excellent and all-too-often overlooked point. The original
PC had the power out for the old monochrome monitors, but the color
monitors had a regular power plug. They were not made to be plugged
into the back of the PC because the power out on the supply and the
supply's on/off switch weren't made to handle the higher current of the
color monitor.
So yes, having the first PS's on/off switch handle two power supplies is
really a heavy burden, which can and probably will cause it to fail
prematurely.
But then power supplies are cheap..