Is this a bad idea?

[Czarles]

Creating a Y type connector plugging two power supplys into one? or would that result in an over voltage?

 

[texasgulag]

I wouldn't touch that with a ten foot wooden pole.

 

[Applicator]

Hiya,
I'm an electrical engineer in power systems that works for a distribution company in Australia.

The danger is too much current not over voltage (in fact your volts will actually drop with the increased current supplied). Power (read heat) is related to the square of the current. The more heat you have the more likely to damage the wiring in your house, so that's why you will have a service fuse which should blow at a current less than the rating of your wiring. So as long as there isn't too much current being supplied through the one wall socket there really isn't a problem.

In my house I have a two 4 board supplies connected in series because I have lots of plugs that supply little things like a camera charger, mouse charger, mp3 charger, modem etc. If you are supplying multiple computers or TVs, speakers etc I would think that's a bad idea and should be avoided.

Hope this helps.

Applicator

 

[pengwin]

yah im not gonna argue with mr. ee up there

for those of u who didnt kno EE = Electrical engineering, my bro is gonna be an ee, i get his stupid IEEEEEEE..E? magazines

 

[clue69less]

Creating a Y type connector plugging two power supplys into one? or would that result in an over voltage?

If you're thinking of getting more juice for your PC, just use one PS for the mobo and the other for the peripherals. I saw a thread about this somewhere with some specifics but I'm not sure where that was...

 

[RichPLS]

If you use heavy grade wire and solid connections you should not have any trouble running two 550 watt PSU's off of one power cord.

Most modern wiring systems in residences will support the load.

 

[Czarles]

and on second thought, (that is 40 wires, or 48... a lot) What is the easiest way to turn two power supplys on at the same time? Two additional wires from ground and power on running to ground and power on on the second power supply?

 

[doolittle]

Clue69Less is on the right track for you, essentially you want a "poor mans dual rail" power supply where one is only plugged in to the mobo and one to power everything else. I have done this a couple of times when I was too cheap to get a high-power PS unit with my new GPU.

Here is a helpful link...
Using a Second Power Supply @ directron

The main concern with sharing 2 power supplies over the same wire is the difference in voltage levels, and I woud worry about back-current that would be trying to pushed over to the lower voltage power supply. Be safe, and don't share wires between the two units - the chassis common ground is all you should need.

 

[Guest]

The danger is too much current not over voltage (in fact your volts will actually drop with the increased current supplied).

Huh? That doesn't even make any sense.

The real reason why it isn't a good idea to tie the supplie in parallel is that one power supplies regulator will swamp out the other power supplies regulator. Due to regulator output voltage tolerance differences one power supply will be doing all it can to bring the other supply up to what it percieves as the correct voltage while the other supply will be doing the opposite...everything it can do to bring the other supply down to what it percieves as the corrrect voltage. It is a tug of war of sorts that is only over after one of the players can no longer play. Smoke!

Even with identical supplies this will be a problem since even among identical voltage regulators there will be an accuracy tolerance which is nonzero, not to mention a slightly varying output impedance among parts of the same type.

This will happen on a rail by rail basis to all of the rails you tied together.

Edit: PS it is likely ther will be no overvoltage, but one of your supplies and maybe both will die. Even when they are not dead yet you won't be getting the intended functionality. The other ideas about 2 supplies powering different sets of hardware is a better idea, and could work.

 

[delanooch]

why? Y ??

 

[jap0nes]

why do you need such thing?

 

[Czarles]

Two semi trustworthy "550" watt power supplys 40.

The expensive stuff everyone says to buy.... 75....



Not only does it save me money, but it saves me money.


Even if they are 550 max and battle tested at 400, 800 watts for 40 dollars and it works well.

 

[jap0nes]

My girlfriend's specs:

A64 Venice 3000+
1GB ram
ATI X600XT
Seagate 160GB
DVD-RW

all running on a generic 500W $20 with no problems at all
i think it's funny at this forum coz every single problem... since a computer not booting to graphics artifacts.. the first thing they say: your PSU is a crap, buy a brand-name 500+W.

Even lower spec'ed computers, like a XP1800+ 9800Pro with a 300W they say the same sh*t.
I also noticed people here like to blame components instead of helping people diagnose the right problem. I've seen a lot of posts where it was a driver problem, but everybody got telling to change the PSU. So, let's say the guy just goes and buy a new PSU and cant solve his problem.

My point:

Buy one good quality PSU according to your needs and you are good to go. If you dont have any high end system i'd risk to say that any 400-500W generic PSU would do the job.
Instead of spending a lot of money on a PSU, try to look for something that would improve the quality of the energy your PSU uses, like a no-break or something.
Believing your electric company delivers high quality energy to your home is at least stupid. A brand-name PSU wont solve any problem if your electric company sucks.

EDIT:
try to connect a multimeter to your computer's outlet and see if it delivers the right voltage, steady, no peaks or lowers and you'll see what i'm talking about.
i would never ever connect my computer directly to the outlet. Also, try to invest on a good grounding system at your home.

 

[Applicator]

Ok, after re-reading this topic I can see what the original poster is talking about. He is talking about paralleling two PSUs. In my post I was talking about putting two four plug power boards in series to get 7 plugs out of one outlet which is totally different.

Have to agree that putting 2 PSUs in parallel is a bad idea due to different impedances of the units and output voltages. Knewton summed it up well when he said there would be a tug of war. No two devices will be the same, even from the same supplier. Better off just having one big unit and it's way less hassle anyway.

 

[Czarles]

I think i'm gonna use one for powering the board and the other for the drives and such. Thanks to the dude who linked that one setup.... I wouldn't have thought of using one of the molex connectors and running it to the power on. (I've used the power on manualy but, not to a molex, just shortin it with a peice of wire.).

Thanks.

 

[MU_Engineer]

Yeah, the wiring *should,* but it needs to be a dedicated circuit, which I am sure it is not. I have had my breakers trip in my apartment because there are two 15-amp branches feeding all of the outlets. Putting a computer, lamp, and running a vacuum off certain outlets (not the same one) will trip it every time. I have learned where I can and can't plug in stuff like that.

Thank goodness I am moving into a house with more than two branch circuits after my lease is up. Some are even 20-amp circuits- yay! My parents' old house had dual 200-amp main panels running on an independent input service line and every branch was 20 amps and there were about 4 outlets to a branch. We didn't trip a breaker outside the wood shop once in the dozen years we lived there