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Dual PSU How-Tos

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Can someone pls help me clarify these?

- Are ATX PSUs capable of running in PARARELL without isolating the GND ie. can I simple solder +5V, +12V wires from PSU1 to the corresponding wires on PSU2 to get more AMPS?

- Are ATX PSUs capable of running in SERIAL by ISOLATING the GND of PSU2 only and connect +12V from PSU2 to GND on PSU1 as per the guide to get more VOLT?

Thank you.
 
Just a silly question - with power supplies hitting the 500+ watt mark - why would dual psu's be needed?

Just curious, thas all....
 
Lots of people have a couple or more low watt PSUs, and don't want to spend the loot. Others want to perhaps power a peltier in extreme cooling circumstances. Some just like to play.
 
I did it. It works on ATX PSUs too.
Dual 250W ATX PSUs in pararell to power a 226W Peltier.
Each one is capable of 10 amps on +12V line.
It is my cheap peltier PSU.

I isolated the GND of one PSU.
Connect the Green line to GND.
Then connect +12V line of each PSU together to power a peltier.
I don't use diode to isolate each line.
I dummy-load on +5, +5VSB, and +3.3V lines about 1 amp each.
 
Go to directron, and with a 10$ purchase you can get an on off switch for 1$, just mount it on one of the bezel covers and plop it on when you need it ;) that's wut im planning on doing.
 
Anyoen have a tutorial on linking an ATX and an AT? At least by splicign the hot wire for turn on. I want to use up some old AT PSUs I have lying around to power the fans and lights. I want to hpush one switch and have both turn on.
 
Not so much the green wire, but pin 14. Quite a few PSUs have a slightly different wire color scheme.

As to combining, I'd probably recommend using a relay, as ATs switch on and off via their own switch.
 
I've slightly modified speedy3d's pictures to fit my needs, anyone see a problem with wiring up the 2nd PSU this way?
dualPSU.JPG


basicly, just take the 3 wires from the 2nd PSU and splice them into the main PSU's power connector.
Ignore where it says Ysplitter, I just forgot to erase that.
 
KnowlesTech said:
Anyoen have a tutorial on linking an ATX and an AT? At least by splicign the hot wire for turn on. I want to use up some old AT PSUs I have lying around to power the fans and lights. I want to hpush one switch and have both turn on.

Does anyone have some info on using an old AT PSU to suplement your current ATX PSU with the goal of stabilizing the 5v line, or seperating the 5v and 3.3v lines so that one is running off each power supplly? I don't really care I have to flip 2 switches or anything, just want to know if I can use an old AT to try and help my low 5v line.

On a side note, if you really wanted the powered on by one switch, is there some way you could link the power on wires going to the mother board header for the ATX switch to the flip switch on the AT so that when you fired up the AT the mobo would triger the ATX at the same time?
 
FishDog3 said:


Does anyone have some info on using an old AT PSU to suplement your current ATX PSU with the goal of stabilizing the 5v line, or seperating the 5v and 3.3v lines so that one is running off each power supplly? I don't really care I have to flip 2 switches or anything, just want to know if I can use an old AT to try and help my low 5v line.

On a side note, if you really wanted the powered on by one switch, is there some way you could link the power on wires going to the mother board header for the ATX switch to the flip switch on the AT so that when you fired up the AT the mobo would triger the ATX at the same time?

My simple solution would be to just get a 12v car relay and splice into the molex connectors for your 12v trigger (which would turn on the AT power supply). Or at least in my case that's all I have to do is make a connection. Of course under the stipulation that the 5v line on the AT supply is loaded. Why don't you just run your peripherals from your AT supply, and leave your ATX to run your mobo? I'm about to add 5 scsi drives to a raid 5 array, and plan to use the AT supply for those drives, fans etc, and leave the main PSU for everything else.

It'd probably be "better" to combine their loads or something more complicated, and having built a couple basic power supplies, I should want to get into this sorta thing, but part of me wants to just tap both of them at the same time and leave the internals the way the engineers designed them. The whole understanding each load and how they come together and/or work against each other is beyond my knowledge... I think by the time you balance which one needs which load, you'll probably know enough to have just built that one big supply in the first place. My vote, best bang for the buck with no jolts, 5$ relay.
 
FishDog3 said:


Does anyone have some info on using an old AT PSU to suplement your current ATX PSU with the goal of stabilizing the 5v line, or seperating the 5v and 3.3v lines so that one is running off each power supplly? I don't really care I have to flip 2 switches or anything, just want to know if I can use an old AT to try and help my low 5v line.

On a side note, if you really wanted the powered on by one switch, is there some way you could link the power on wires going to the mother board header for the ATX switch to the flip switch on the AT so that when you fired up the AT the mobo would triger the ATX at the same time?

I too would like to split the 3.3V and 5V lines. There are 3 3.3V cables going to the motherboard atx connector, can I just switch those cables with the ones from PSU#2?
 
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