Adapting a server PSU to power the gfx cards
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It wouldn’t be the project to start with, that’s for sure. You’re much better off starting with something small that’s a little more forgiving of learning.
Those caps in there have some tremendous voltage potential, and can KILL YOU, even if the damn thing is turned off AND unplugged. I’m not kidding. I’ll say it again: It’s powered off, it’s not plugged into the wall, and it has the potential to cause death. I used a 100k ohm dummy load to drain the caps individually before working on it, but I happen to have one laying around from my ham radio days. If you’re going to do this, learn about how to discharge a capacitor safely first.
Don’t believe me? Watch what a really big cap can do: [url=http://www.youtube.com/watch?v=coW1RHUsf_I#ws]Big Capacitor Safety[/url]
I’ve seen people discharge a cap with a screwdriver, but god help you if you’re not holding the plastic handle and are accidentally touching the metal. This is the equivalent of moving a tank of gas around while holding a blowtorch.
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[quote name=“Kevlar” post=“45659” timestamp=“1387321943”]
It wouldn’t be the project to start with, that’s for sure. You’re much better off starting with something small that’s a little more forgiving of learning.Those caps in there have some tremendous voltage potential, and can KILL YOU, even if the damn thing is turned off AND unplugged. I’m not kidding. I’ll say it again: It’s powered off, it’s not plugged into the wall, and it has the potential to cause death. I used a 100k ohm dummy load to drain the caps individually before working on it, but I happen to have one laying around from my ham radio days. If you’re going to do this, learn about how to discharge a capacitor safely first.
Don’t believe me? Watch what a really big cap can do: [url=http://www.youtube.com/watch?v=coW1RHUsf_I#ws]Big Capacitor Safety[/url]
I’ve seen people discharge a cap with a screwdriver, but god help you if you’re not holding the plastic handle and are accidentally touching the metal. This is the equivalent of moving a tank of gas around while holding a blowtorch.
[/quote]wow…
ok, so if I don’t happen to have a dummy load lying around, and I want to drain the caps with a screw driver, what sort of precautions should I take?Would tying a grounding wire to the metal bit of screwdriver and then tying the damned thing to a 6 foot pole be too much? Or should I go with something longer?
I sort of like not needing a pacemaker…Also, how many caps are actually in there that require draining?
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[quote name=“Max.Wyght” post=“45665” timestamp=“1387323288”]
[quote author=Kevlar link=topic=6146.msg45659#msg45659 date=1387321943]
It wouldn’t be the project to start with, that’s for sure. You’re much better off starting with something small that’s a little more forgiving of learning.Those caps in there have some tremendous voltage potential, and can KILL YOU, even if the damn thing is turned off AND unplugged. I’m not kidding. I’ll say it again: It’s powered off, it’s not plugged into the wall, and it has the potential to cause death. I used a 100k ohm dummy load to drain the caps individually before working on it, but I happen to have one laying around from my ham radio days. If you’re going to do this, learn about how to discharge a capacitor safely first.
Don’t believe me? Watch what a really big cap can do: [url=http://www.youtube.com/watch?v=coW1RHUsf_I#ws]Big Capacitor Safety[/url]
I’ve seen people discharge a cap with a screwdriver, but god help you if you’re not holding the plastic handle and are accidentally touching the metal. This is the equivalent of moving a tank of gas around while holding a blowtorch.
[/quote]wow…
ok, so if I don’t happen to have a dummy load lying around, and I want to drain the caps with a screw driver, what sort of precautions should I take?Would tying a grounding wire to the metal bit of screwdriver and then tying the damned thing to a 6 foot pole be too much? Or should I go with something longer?
I sort of like not needing a pacemaker…Also, how many caps are actually in there that require draining?
[/quote]That would be worse. You want to equalize the potential across the caps, not short it to ground.
I think there was at least 3 big ones in the one I was taking apart. Your mileage may vary.
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[quote name=“Kevlar” post=“45676” timestamp=“1387324743”]
That would be worse. You want to equalize the potential across the caps, not short it to ground.I think there was at least 3 big ones in the one I was taking apart. Your mileage may vary.
[/quote]How do I go about equalizing them?
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[quote name=“Max.Wyght” post=“45677” timestamp=“1387325320”]
[quote author=Kevlar link=topic=6146.msg45676#msg45676 date=1387324743]
That would be worse. You want to equalize the potential across the caps, not short it to ground.I think there was at least 3 big ones in the one I was taking apart. Your mileage may vary.
[/quote]How do I go about equalizing them?
[/quote]Well like I said I used a dummy load because that’s going to be the least dangerous and will drain it slowly over a few seconds instead of in a bright flash of sparks. But if you go the metal screwdriver route, watch out for broken plastic and don’t stand in any pools of water.
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[quote name=“Kevlar” post=“45680” timestamp=“1387326102”]
[quote author=Max.Wyght link=topic=6146.msg45677#msg45677 date=1387325320]
[quote author=Kevlar link=topic=6146.msg45676#msg45676 date=1387324743]
That would be worse. You want to equalize the potential across the caps, not short it to ground.I think there was at least 3 big ones in the one I was taking apart. Your mileage may vary.
[/quote]How do I go about equalizing them?
[/quote]Well like I said I used a dummy load because that’s going to be the least dangerous and will drain it slowly over a few seconds instead of in a bright flash of sparks. But if you go the metal screwdriver route, watch out for broken plastic and don’t stand in any pools of water.
[/quote]That’s a given.
but if I want to get a dummy load, how powerful should it be, and where could I get one?
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You can use a resistor of any size, really, so long as it’s rated for more than a couple watts. Here’s a nice 8ohm one rated for 100 watts that should fit the bill nicely for what you’re doing: [url=http://www.parts-express.com/8-ohm-100w-non-inductive-dummy-load-resistor–019-020]http://www.parts-express.com/8-ohm-100w-non-inductive-dummy-load-resistor--019-020[/url]
This is the ‘professional engineer’ solution, mind you. You can still go the screwdriver route, but if you burn your board in doing so, don’t say I didn’t warn you.
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O_o How da hell you s’pose to connect that to the cards? And yes CHEAP. Holy sheet.
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[quote name=“Kevlar” post=“45706” timestamp=“1387331360”]
You can use a resistor of any size, really, so long as it’s rated for more than a couple watts. Here’s a nice 8ohm one rated for 100 watts that should fit the bill nicely for what you’re doing: [url=http://www.parts-express.com/8-ohm-100w-non-inductive-dummy-load-resistor–019-020]http://www.parts-express.com/8-ohm-100w-non-inductive-dummy-load-resistor--019-020[/url]This is the ‘professional engineer’ solution, mind you. You can still go the screwdriver route, but if you burn your board in doing so, don’t say I didn’t warn you.
[/quote]Could you post the schematics on where to solder everything and how to connect it to power the gpus alone?
will send 100 ftc once my rig starts working.
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[quote name=“Max.Wyght” post=“46707” timestamp=“1387653727”]
Could you post the schematics on where to solder everything and how to connect it to power the gpus alone?will send 100 ftc once my rig starts working.
[/quote]Max.Wyght I with Kevlar on this one, and a small word of warning if your having to ask for this level of information maybe you shouldn’t be thinking about messing with stuff like this.
A good few years ago when in collage, I remember being in a lab messing around with PSU’s and one of the lads ending up on the floor dribbling and shaking because he wasn’t paying attention! after the paramedics had been and given him the all clear all he said was “I didn’t think it was going to bite, as it was unplugged!”
If you insist on this adventure, please please please promise us that you will do a lot of research before you start, I don’t want to read in the new that a fellow miner has blown himself, or his house up messing about with an old HP PSU
UM
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I don’t have schematics or pictures, as I said I did it with a multi-meter and a lot of know-how. You’d need the same because HP power supplies come in all shapes and configurations.
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If i were you i wouldn’t risk death and just buy a seasonic :P
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[quote name=“uncle_muddy” post=“46708” timestamp=“1387654151”]
Max.Wyght I with Kevlar on this one, and a small word of warning if your having to ask for this level of information maybe you shouldn’t be thinking about messing with stuff like this.A good few years ago when in collage, I remember being in a lab messing around with PSU’s and one of the lads ending up on the floor dribbling and shaking because he wasn’t paying attention! after the paramedics had been and given him the all clear all he said was “I didn’t think it was going to bite, as it was unplugged!”
If you insist on this adventure, please please please promise us that you will do a lot of research before you start, I don’t want to read in the new that a fellow miner has blown himself, or his house up messing about with an old HP PSU
UM
[/quote]Luckily, I’m an extremely cautious bastard.
I know that even unplugged PSUs are dangerous(Whenever I clean up my desktop I make sure to kill/drain/whatever you call the PSU, by first unplugging it, and then shorting the power inlet, and working only on a wooden surface).I was hoping that he could provide me with at least an image of the solders so that I won’t have to research as much, but unfortunately it’s not the case.
That leaves me two options;
Research the bloody thing till my eyes bleed, or talk to my old man… *Shudder*[quote author=Kevlar link=topic=6146.msg46720#msg46720 date=1387658806]
I don’t have schematics or pictures, as I said I did it with a multi-meter and a lot of know-how. You’d need the same because HP power supplies come in all shapes and configurations.
[/quote]Well…
Thanks anyways :)[quote author=aatje92 link=topic=6146.msg46799#msg46799 date=1387695506]
If i were you i wouldn’t risk death and just buy a seasonic :P
[/quote]It’s not just about saving 300$(More to the tune of 1200, but w/e).
If I do this right, I’ll have gained an actual life skill.
I’ll level up in a way. -
And if you fail, you’re dead. Still your choice tho ;)
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[quote name=“aatje92” post=“47269” timestamp=“1387870842”]
And if you fail, you’re dead. Still your choice tho ;)
[/quote]Yeah, I gave up on that.
