How to build your own power supply?

[gigabytecoin]

I am considering spending almost $1,000 on 3-4 gold rated PSUs.

Seems to me they are little more than transformers.

If I could purchase 4*$30 PSUs simply to run the motherboard/cpu power... could I note create a massive single 12 volt rail that distributes power to say 30-40 video cards via pcie connectors at once?

I guess it would really suck if THAT power supply broke down... but still - anybody tried it or similar?

[bcpokey]

Not to be a jerk, but that sounds like a really good way to kill yourself. Playing with 10+ amps is not a good idea.

Yes PSUs are transformers, but they're also filters and some other stuff.

[gigabytecoin]

Not to be a jerk, but that sounds like a really good way to kill yourself. Playing with 10+ amps is not a good idea.

Yes PSUs are transformers, but they're also filters and some other stuff.

No offense taken! I don't know much about electricity yet... but it sounds like a pretty simply job.

[Uzza]

I don't know much about electricity yet... but it sounds like a pretty simply job.

That's the last phrase of someone gunning for the Darwin award.

Seriously, playing with electricity that contains enough amps to kill you outright is NOT something that is recommended, unless that is your job and you've got education to back it up.

[Ibisy]

I don't know much about electricity yet... but it sounds like a pretty simply job.

Famous last words 

[RaTTuS]

1) go and get yourself trained for electial work
2) then think about what you're doing
3) buy relevent PSU's
...

in other words - don't .
please it's not worth it - you'll kill yourslef , burn the place down and kill others.

[WesleyK]

Not to be a jerk, but that sounds like a really good way to kill yourself. Playing with 10+ amps is not a good idea.

Yes PSUs are transformers, but they're also filters and some other stuff.

No offense taken! I don't know much about electricity yet... but it sounds like a pretty simply job.

Well... it's not . A simple 12V 2A power supply is no problem, even for beginners, but these high amounts of currents require serious designs.

[rb1205]

I don't know much about electricity yet... but it sounds like a pretty simply job.

That's the last phrase of someone gunning for the Darwin award.

Seriously, playing with electricity that contains enough amps to kill you outright is NOT something that is recommended, unless that is your job and you've got education to back it up.

Not at all, ampere don't kill you. Even heard about someone being electrocuted by a car battery? I guess not. And you can easly get hundreds of Amperes out of them

Electricity starts to be harmful at about 50 Volts.

BTW, PSU are not transformer, they are AC/DC switching units (note the plural). You can't just connect some of them together, you'll just end up frying all your hardware.

[Zagitta]

Not to be a jerk, but that sounds like a really good way to kill yourself. Playing with 10+ amps is not a good idea.

Yes PSUs are transformers, but they're also filters and some other stuff.

No offense taken! I don't know much about electricity yet... but it sounds like a pretty simply job.

It SOUNDS simple yes but that's merly because you don't know anything about it... Don't throw yourself at it because:
First of all it will take at least a month to just read up all the theory behind (and that's assuming you're damn smart)
Secondly there's a huge bunch of safety hazards
Thirdly it's a huge investment because quality capacitors aren't cheap and you'll need that for 24/7 operation

Last but not least: It's MUCH more difficult to build a big powersupply rather than a lot of small ones...

Moral of the story? Don't waste your time on it

[bcpokey]

Here is a look inside a high grade high watt power supply:

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story4&reid=189

[Zagitta]

still not convinced? have a look at this http://www.pavouk.org/hw/en_atxps.html

[bcpokey]

I don't know much about electricity yet... but it sounds like a pretty simply job.

That's the last phrase of someone gunning for the Darwin award.

Seriously, playing with electricity that contains enough amps to kill you outright is NOT something that is recommended, unless that is your job and you've got education to back it up.

Not at all, ampere don't kill you. Even heard about someone being electrocuted by a car battery? I guess not. And you can easly get hundreds of Amperes out of them

Electricity starts to be harmful at about 50 Volts.

BTW, PSU are not transformer, they are AC/DC switching units (note the plural). You can't just connect some of them together, you'll just end up frying all your hardware.

What the crap are you talking about? 100mA can stop your heart. Why would people go around being electrocuted by a car battery? I turn my car on with a key, not by shorting the leads with my body.

And yes, PSUs are transformers, at least functionally and they incorporate transformers as well as power switches. As I said they are complex creations and not to be made at home.

[rb1205]

What the crap are you talking about? 100mA can stop your heart. Why would people go around being electrocuted by a car battery? I turn my car on with a key, not by shorting the leads with my body.

And yes, PSUs are transformers, at least functionally and they incorporate transformers as well as power switches. As I said they are complex creations and not to be made at home.

Yes, 100 mA can kill you. But, to make that current to flow thru your body, it needs to have a given potential (because, as you will know, our body is not a good conductor). Depending on a lot of factor (skin resistance, humidity, position of the electrodes,...) the voltage that can kill you starts from 50 VAC at the very least, and goes up to several hundreds. You can't even feel anything if the potential is only 12 VDC, disregarding the maximum current that it can generate.

[BombaUcigasa]

Expensive PSUs offer greater efficiency. Considering our purpose, it would be stupid to pay 100$ less for a PSU and pay 50$ more every month in electrical bills. Not only that, but you need a PSU that offers:
- the required power drain
- filtering and leveling depending on external supply and internal PC power usage
- protection of itself and PC components in extreme cases

Would you pay 100$ less for a PSU and risk destroying your 900$ video cards at the next brown-out?

[Cluster2k]

PSUs take a lot of time and skill to design correctly, and to use quality parts.

I was at a local PC parts retailer recently and saw someone walk in and ask for a SHAW brand 680 watt power supply for $17, while I was buying a Cooler Master GX 750 watt for $115 for my bitcoin set up.  Over six times the price for just a little more power?  You'd think I'm crazy to pay that, right?  Well, the Cooler Master will actually deliver its rated power, with high efficiency, stable voltage and current, into multiple voltage rails and do that for years to come.  The SHAW will do none of that, and likely blow up (not joking) and take the customer's other PC parts with it.

The moral of the story is high quality, high current power supplies cost more because they are so much better than the cheap brands and certainly anything you can build yourself (unless you're en electrical engineer).  

Follow the advice of other forum members and please don't attempt to dismantle or build your own PSU.

[klayus]

actually 25mA of current has to go through your heart to stop it. knowing that the human body has a resistance of couple of Mohms(lets use 1 for the equation although is kinda bigger) the equation I=V/R is I= 12/1000000 = 0.000012 Amps of current in your body. that wont kill you, it will only make you stronger

[nixxle]

Seems in line with them miners on these forums that have their motherboard running on the carpet with fans blowing into it and all that.

Bitcoins get more expensive everytime there's a big story somewhere. A bitcoin Death would really help us get out this 25 / 30 USD lameness we're in.

Take one for the team!

[d3m0n1q_733rz]

Hey here's some advice; if you're looking to join multiple rails together, some PSUs have an option they like to call turbo that joins together all of its 12V rails.  However, I've heard that running on single rail too long will often cause the PSU to die prematurely on high loads.  I know my Tagan can do it, but it's just 800W.

Here's a multi-rail 1200W system http://www.newegg.com/Product/Product.aspx?Item=N82E16817371043  It'll handle just about anything you throw at it.
Here's a single-rail 1200W system http://www.newegg.com/Product/Product.aspx?Item=N82E16817171055  It'll handle what you want too, but any energy spikes you get will go through the whole system.

I had a HDD cause problems with my DVD burner a while back because they were on the same rail and the DVD burner was having power spikes on writes which was causing failed burns.  Putting them on separate rails allowed for steady current to my burner and my burns came out nearly flawless.  So I recommend multi-rail for high-pull hardware.  Just be sure that the specs allow the wattage it needs per rail.  12V * Wattage per rail = output per connector line.  The above should handle around 3 HD6990 cards unofficially without problem and leaving 300W for the rest of your system.  It's cutting it close, but I don't imagine your CPU using more than 150W on an i7 and newer HDDs will use about 11 watts max so you're good to go.
Don't go thinking that the loss in available power per rail makes it less efficient.  The fact is that you'll probably never need 360W on a single rail anyway so the other rails can more than handle the loads on their own while mitigating power spikes making it more efficient on the PFC side of things.

[darkpandora]

power supply is not something simple.. i have studied electronics for 3 years in high school and computer related electronics is not "simple job". psu is devided in 2 groups in the circuit, 1 side high voltage and 1 side low voltage, and there are lots of chips involved. so don't even bother programming chips, its pain in the head, believe me.

[pwnyboy]

I am considering spending almost $1,000 on 3-4 gold rated PSUs.

Seems to me they are little more than transformers.

If I could purchase 4*$30 PSUs simply to run the motherboard/cpu power... could I note create a massive single 12 volt rail that distributes power to say 30-40 video cards via pcie connectors at once?

I guess it would really suck if THAT power supply broke down... but still - anybody tried it or similar?

I looked at the viability of doing something similar, using 48 volt telecom rectifiers as a PSU (but flipping around the ground reference, because they're all negative voltage).  They deliver substantial current on the cheap (200a at 48v, so 800a at 12v if you run them through a bunch of big ass batteries).  But at the end of the day you will have spent 1k on batteries and regulators, plus cabling, plus capacitors and diodes, yada yada yada.  By the time it's all over, you'll end up with 1.5k worth of crap, and a whole bunch of work, just to power up your "30" video cards, with a single point of failure, and a bunch of electronics that are hard to understand and hard to work on.  I looked at other options, like inexpensive 12 volt battery chargers, no dice.. they're too expensive.  The cheapest option you have is the $1000 worth of PSUs.

By the way, I read your other thread about the smoked components.. I've got a pretty good idea of what happened and why, based on a critical omission on your part while describing your setup.  Of course I'm going to be a troll and not reveal what it is, both because it's already been asked/answered on the forum at least once that I'm aware of, and because I'm not going to help anyone devalue my investment in mining any further by making it any cheaper for you, or anyone else, to do business.  Knowledge is power, and when you don't have it, sometimes you have to pay for someone else's, i.e. in the form of those expensive PSUs.  That smoke should make you less bullish on playing with fire, not more.

Take on for the team!

He seems pretty determined to do so, doesn't he?