question about two psu's

[mygarbage2000]

Can anybody tell me if it is possible to use two psu's simultaneously. For example one to power the monitor and hdd's and the other for the m/b. i have two 250 W units and here in india you don't get psu's rated for higher than 300W. I have been experiencing random reboots while using one of the 250W units. I think it is psu related because it reboots for example when accessing the cd drive and when starting a 3d game. If anyone has tried this or knows anything please let me know. thanks for your time guys.

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[ejsmith2]

You're talking about running them in parallel.

Dude, it's been talked about before, and I've thought about doing it before (not too long ago, I had two 300w psu's, same brand and model) but I have never done it.

If your psu's are the exact same model and brand, and have similar "quality" or "ok" stickers in the same place, then they are close enough.

Start wiring. I'd use a soldier gun just to make sure your resistances and connections are very close. Flux everything.

Double check your wires/connectors, and crank it up. The voltages have to be close enough to not cause a a tremendous backlash through the transformers, but either way, you'll still won't get 100% out of each psu.

Two 250's will net you about 400-450w, I'm guessing.

 

[Crashman]

Here's what I would do to run two power supplies. Take an old AT power supply, the ones before motherboard detection, and use that to power all the drives. Hook your other power supply to the motherboard only. AT power supplies are hard switched, so turn that one on before you start your system. Your drives should spin up by themselves. Now switch on the system.

What's the frequency, Kenneth?

 

[mygarbage2000]

i don't want to run them in parallel. i want to use one for my hdd's and the other for my m/b. i guess i will have to use a power supply with a hard switch. ej i do not knoe the details of setting up a parallel system. it sounds interesting. if you could help me out i could give it a shot. thanks for your time.

XP 1800+
GA-7VTXE+
256 MB Infineon CL2
Leadtek gf3 ti 200
sb live! de 5.1

 

[ejsmith2]

Believe it or not, using one psu to power your hard disk/cdrom/fans and the other to power your mainboard won't help you out. At least, it doesn't sound like it in your case. If you were getting snowy screens, green lines, and general graphix glitches, then you would probably be within the couple of amps region where clicking your storage over would help out.

That hard disk/cdrom/cdrw/fans pulls from the 12v rail to power it's motor. It pulls a couple of amps off the 5v rail to power the electronics, but that amounts to 1 or 2 amps per device. Overall, unless you're running Raid5, your storage stuff just doesn't pull the psu down much.

That processor will yank upwards of 21 amps off the 3.3v rail. That GF3 will yank upwards of 12 amps, real close to 15 when you o/c and get heavy into a game like Medal of Honor. The SBlive pulls close to 5 at max output, and your mainboard (memory, north/south bridge) pulls about another 10.

If you're running a peltier, then running those two psu's concurrently is definatly a good option. One powers the peltier, the other runs the computer and flips on the peltier psu. I did this for a month with a relay, so that I could keep both psu's competely stock.

 

[mygarbage2000]

thanks ej, that is some valuable info right there. looks like a new psu is on the way. i will look at the max amp on each rail according to your specs. thanks again man. great help.

XP 1800+
GA-7VTXE+
256 MB Infineon CL2
Leadtek gf3 ti 200
sb live! de 5.1

 

[jamarno]

Do not wire the supplies together. A power supply tries to regulate its own output -- too high and it tries to turn it down, too low and it tries to turn it up, and the adjustments will be made successfully. But a supply can adjust only its own outputs, not another supply's, so if you connect two supplies together, they won't be able to regulate the common outputs right, and if the time delay between the adjustment and change in output is just right, the supply could start to resonate (like speaker feedback), and this often causes it to burn out. Even if the two supplies are identical, they won't really be identical.

 

[ejsmith2]

"often causes it to burn out"

But is it a really spectacular burn out?

That's what I'm wondering. Like when Gandalf launches that Flaming Dragon one, and it makes 3 passes over the crowd before detonating over the river.

Will the psu careem around the room like a Roman Candle ball? That's what I would like to know...

 

[mygarbage2000]

lol! roman candle ball. Anyway thanks guys. and i am not going to wire the two supplies together so don't wait for the burnout!

XP 1800+
GA-7VTXE+
256 MB Infineon CL2
Leadtek gf3 ti 200
sb live! de 5.1

 

[cakecake]

<A HREF="http://www.hardocp.com/image.html?image=MTAxMTI0Mzg3NVpjZDBJbldpMVBfMl8xM19sLmpwZw==" target="_new">http://www.hardocp.com/image.html?image=MTAxMTI0Mzg3NVpjZDBJbldpMVBfMl8xM19sLmpwZw==</A>

An image of what you can do to fool the PSU into thinking it's plugged in. I would use a PSU to power the HDD and CDROM and fans and a separate PSU not connected to the first PSU to power the mainboard. That would probably be the best and most stable way of using PSU's together.

Censorship makes us so much more creative.

 

[roberticamen]

ENGR. ICAMEN: 2 power supply connected together ?


you can used diode block if you connect 2 power supply together to work simultaneously, the used of the diode will protect the currect & voltages output of each power supply not to sink to each other power supply output just a forward bias only.

 

[Kari]

7 year old thread, nice one! 0_o

and there are 24pin y-cable thingies, that are designed just to get two cpus to work and start up together...

 

[roberticamen]

yes there are 24 cables wright? but we need only 3.3v,12v,5v wright? the most important voltages was 5v ok it carried around 30A, the other colored wire other than the orange, yellow and the color of 3.3v was not needed to used diode ok!!

used and tie up together the green colored wire both PSU units to switch the power supplies at the same time.

i used this method in my internet cafe and in my game server it works.........