# How to run a PSU without being in pc



## whc.demo (Feb 9, 2007)

how do i run a psu without it being plugged into my pc?


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## J0N (Feb 9, 2007)

For what purpose?


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## Frogger (Feb 9, 2007)

whc.demo said:


> how do i run a psu without it being plugged into my pc?



short plugs 14/15 ..pic


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## Protius (Feb 9, 2007)

with a paper clip


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## Nitro-Max (Feb 10, 2007)

Remember thats only a 20pin !! are the 24 pin ones any different?.


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## Nitro-Max (Feb 10, 2007)

My 600watt Ezcool has 48amp rails and if u guys knew how much a 48amp power supply was for a CB or ham Radio you would get ideas what you could do with it outside the computer i am curious also what he wants to use it for? maybe for the garden shed / garage as multi purpose power unit.


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## whc.demo (Feb 10, 2007)

heyguys, yes i wanted a mulitple psu set up, i have connect the green earth wire from my 2nd psu's 20 pin connector to my "main" psu's green earth wire.

I have the main psu running mobo, cpu and gfx, the 2nd psu is running my hdd's and optical drives, works very well so far 


thanks for the replies


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## Nitro-Max (Feb 10, 2007)

whc.demo said:


> heyguys, yes i wanted a mulitple psu set up, i have connect the green earth wire from my 2nd psu's 20 pin connector to my "main" psu's green earth wire.
> 
> I have the main psu running mobo, cpu and gfx, the 2nd psu is running my hdd's and optical drives, works very well so far
> 
> ...



kool well good luck with it


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## Lazzer408 (Feb 10, 2007)

whc.demo said:


> heyguys, yes i wanted a mulitple psu set up, i have connect the green earth wire from my 2nd psu's 20 pin connector to my "main" psu's green earth wire.
> 
> I have the main psu running mobo, cpu and gfx, the 2nd psu is running my hdd's and optical drives, works very well so far
> 
> ...



The green wire isn't an "earth" wire. It's the PS -on signal when grounded. Cool it works. You must have the psu grounds tied together somewhere too.


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## whc.demo (Feb 11, 2007)

lol ok then :S  


yer it works i wonder what i have done then lol...

i noticed when i turn the pc off both psu's turn off, but if i hit the switch on the back of the main psu to turn it off the 2nd psu starts up!


lol i hope it doesnt blow up


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## Lazzer408 (Feb 11, 2007)

whc.demo said:


> lol ok then :S
> 
> 
> yer it works i wonder what i have done then lol...
> ...



The green wire normally pulled high by the psu. It has a small voltage to it. I never actually measured it though. Probably 5v. It is pulled low (grounded) by the motherboard when you press the power button. When the primary powersupply is turned off there is no voltage on the green wire and apperently it has enough resistance to ground that the secondary powersupply sees it and turns on. I can't see any way this will hurt anything though. If you want, you can get a small 5v or 12v relay from Radioshack and connect the relay's coil to one of the primary psu's outputs and connect the green wire and one of the grounds from the secondary psu to the relays normally open switch contacts. This way there is no chance of the secondary powersupply turning on unless that relay is activated by the primary psu. If you would like a diagram just let me know.


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## regan1985 (Feb 15, 2007)

its a good idea and im going to look into it as it saves me spending £250 on a 1000watt psu


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## Nitro-Max (Feb 15, 2007)

is the output on a psu AC or DC ? ive never really looked lol


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## Lazzer408 (Feb 15, 2007)

Nitro-Max said:


> is the output on a psu AC or DC ? ive never really looked lol



DC.
see this...

http://xtronics.com/reference/atx_pinout.htm


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## SupperAssBASS (Feb 15, 2007)

Nice idea, was thinking about it cause I'm using a DTK 300 W PSU, so instead of buying some expensive PSU, will just buy the same DTK for like 20 $!


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## Lazzer408 (Feb 16, 2007)

Here you go. This is the safest way to isolate the PS-ON signal to prevent the aux. psu from powering on if the main psu is unplugged. Use a 12v (or 5v via. red wire on main psu) relay to actuvate the aux. psu. Any relay should be fine but larger relays can have a large flyback spike when turned off. In that case, use a diode wired as shown to catch the spike.






For a retail solution see...

http://www.thermaltake.com/product/Power/PurePower/w0099/w0099.asp

I'm using one of those. Only $44 and it runs my x1950 pro crossfire just fine. It's cool and it's quiet.


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## Nitro-Max (Feb 16, 2007)

Lazzer408 said:


> DC.
> see this...
> 
> http://xtronics.com/reference/atx_pinout.htm



thnx m8 this is always worth knowing


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## overclocker (Feb 16, 2007)

LOL i have been doing this for a long time i have a 450w PS running 3 fans for my laptop made myself a docking station and the 12V rail are not good for big loadeds its auto stuts off maybe you could run some 12 lights but dont think you will be boosting a car with it LMAO. o and dont take the case off the PS with out unplugging it first i forget to and really got a big jolt NOT FUN!


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## Lazzer408 (Feb 16, 2007)

overclocker said:


> LOL i have been doing this for a long time i have a 450w PS running 3 fans for my laptop made myself a docking station and the 12V rail are not good for big loadeds its auto stuts off maybe you could run some 12 lights but dont think you will be boosting a car with it LMAO. o and dont take the case off the PS with out unplugging it first i forget to and really got a big jolt NOT FUN!



Do not take the cover off your psu period. The main capasitor has 160vdc across it and it takes awhile for that to discharge on it's own.

overclocker (I feel like I'm talking to myself here. I have that name on yahoo.) What were you trying to power off a psu that was causing the protection trip?


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## overclocker (Feb 16, 2007)

lol i just forget to shut the PS off wen i was checking the fan haha. and great minds think a lot i gues (overclocker) LOL


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## Nitro-Max (Feb 16, 2007)

I remember working on a homebase power amplifier or linear as some call it its was a bremi 600watt with old glass valves and man do they hold alot of charge it was all switched off. Had one slight slip and touched one threw me across the room i buzzed from head to toe lol felt like a smoked kipper out of water just sat for a good 2 mins just wondering wtf just happend ? play with matches there much safer trust me hehe   .


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## bennix (Feb 21, 2007)

Just connect the green wire and the black one (ground) that should works


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