Topic: How to build your own power supply? - page 2. (Read 16378 times)

PSU is both a transformer and AC/DC switching unit. First you need the transformer to get to proper voltage, then you put in a transistor bridge, few diodes etc. and you got yourself DC. I also would recommend a regulator and few small capacitors and low Ohm resistors, and a heatsink for the regulator(s). The combination of regs, capacitors and resistors should filter everything out

Working with high amperage low voltage is safer than high voltage low amperage IMHO, because the electricity does not "jump" as easily. High voltage is needed for being able to go through highly resistive materials (see Tesla coils for example. That's also why engine spark wiring insulation is such an important factor). My hobby used to be RC cars, and i had 7.2V 400A peak battery packs... I was more worried about getting them pierced while driving (and resulting explosion & fire) than getting a shock.

Here is how you can build it:
http://engknowledge.com/power_supply_design.aspx

I would design it to be quite parallel, meaning multiple transformers, multiple bridges, multiple capacitors etc etc.
So that any single component has smaller impact if it fails on operation, or is otherwise flaky. I would design regulators, capacitors etc. well beyond required spec to reduce risk of failure.

Also, doing it from this low level you could add some basic electronics to handle backup power, see for example: http://www.dreamgreenhouse.com/designs/12v/index.php (links to their UPS project),  http://tech.icrontic.com/articles/super_ups , http://1wt.eu/articles/alix-ups/

Last one is the most intresting one infact

Google is your friend, but i wouldn't suggest trying this with no past experience on the required scale....

I built a power supply for some specialized equipment I built while working on my Physics PhD.  You can easily find the relevant info on how to build a good power supply.

But it is terrible waste of time and money.  You will never do it cheaper than the box you buy from commercial supplier.

It is more than just a transformer (though that is most of the weight).  It is also a diode and a filter.  High current versions of these components are expensive.  Also you will spend a lot on all the little extras, the box, the heat sinks, the switches, the connectors and the cables.  The cables and connectors have to be well made, a lot of failures happen because of bad cables.  Each card requires 6 separate power feeds each with it's own ground, that's twelve wires per card.  If you buy a power supply it comes with the cables!

For building my rigs I went with the best power supplies I could find.  I've built four rigs and spent about $850 for the four supplies.  My first two were 1200 Watt supplies (Antec, on sale $217 each) and I realized based on experience that that was more reserve than needed so my last two supplies were 850 Watts (Corsair $189, Thermaltake, $229) and that seems to be enough to power 4 5850 cards.

Sam

Lol thanks for the kind words

this

it would take some serious effort to build a psu (from scratch) maybe if you found a schematic of a unit that someone had already built and tested.

The best method I know:

1. Order a "fully modular" PSU.
2. Once it arrives plug in all the proper cables in proper holes on the sides of the PSU
3. Profit!

Can you stop arguing about the amps and the health concerns? You don't wear your home-made PSU on your head do you? Just don't touch the case and use a good grounding, no danger, end of story.

Now, resuming. Does anyone know if you can integrate a solar array with an UPS and PSU to have the highest efficiency between the components?

Well yea I built my own power supply for equipments that are use in industrial areas a while back (when my uncle began to cut cost -.-), he paid me close to nothing for the electrical/electronics degree I own. So I know with good planning, precaution and safety into the design, this is definitely possible (even w/o). But I just think it's not recommended.

Actually, it's impossibile to make 30 amps of current flow thru you with only 12V. That's what I'm trying to tell you all: there's this thing called "resistance".

but yes, If you could, It would kill you.

I really don't think that you should even be considering undertaking a project that forces you to ask "Uhh, just how much of this can kill me? What are my chances of survival?"

Honestly, just buy the PSU's. I've never EVER heard of someone building their own.

Yea you could.

But I think it's a lot easier to just bunch a few smaller PSU on a few Systems. It'd be a much easier system to set up, Safer, lesser point of failure. It'd have less of all the problems that were mentioned and more of the benefits that was perceived.

Actually what he asked had to do with ganging up small PSUs in order to make, effectively, one big one.  That's incredibly simple - you need nothing more than a bunch of diodes (albeit, big ones) and a bunch of soldering.  But then what if current-hogging ensues because you didn't know to include components to equalize the voltage between the various PSUs and they start dying right and left?  If the OP doesn't know what a P/N junction is, how a diode works, what forward/reverse bias is, etc., then how would he know how to fix the inevitable problem that pops up when there is one?  How would he know how to fix the design flaw in my aforementioned example, or other unknowns?  As for "fuck all you imma do it anyway", that's what it seemed like.  The question was essentially phrased like.. "I wanna do this, tell me how!"

even 30amps 12v dc wont kill you that's all I wanted to say.

I, personally, have taken 100 kv hand-to-hand intentionally. I was fine. Didn't hurt at all.
Then I burned a pinhead-sized hole in my finger with the arc I drew while moving the electrode away from myself. That hurt a bit more. Healed right up, though.
The PSU in question was a lamp ballast. Ultra-low current (microamps.) I was using it for a mini solderbot.

I've also accidentally touched a 300v flash capacitor. I woke up on the couch with my parents looking down at me in horror. (That was for a portable EMP cannon.)

And I've also played with a gigantic capacitor bank (megafarads!!) at 1 volt. It vaporized the electrodes.

Electricity is not some magic dangerous thing. If you understand it you can be safe with it.

(oh, and don't build your own PSU. if you fuck up you'll kill your graphics card, possibly the mobo as well)

Damn guys, if www.xtremesystems.org was up you'd be in for a TREAT, one of the enthusiasts there built his own 2000+ watt PSU, it was EPIC /sigh another day

I'm glad we heard back from you - I thought you tried this and roasted yourself.

Who'd a thunk this would have caused such a stir???

Went and bought a few OCZ 1250W Golds... thanks for the advice gentlemen!

"Don't try and build your own power supply" has just become the 20th safety tip. gigabytecoin, you are the ballsiest miner out there, care for an interview while you're still in one piece?

While this seems like a dick move, I can at least understand why you feel that way.



This is what I don't understand.  The guy simply asked the viability of making his own PSU's to supply power to the 6-pin PCI-E video card slots only.  (not entire systems which require all the chips / circuitry / logic)
It was a simple question of "would this be something I could do?", and that response of yours is acting like he said "fuck all you imma do it anyway"