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Author: Subject: Power Supply from ATX, DIY
trezza
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[*] posted on 6-3-2011 at 06:13


I once used an old power supply for a chlorate cell, I didn't use any power moderation I just hooked up my electrodes on the 12v rail. About an hour into the electrolysis there was a massive bang and the safety switched turned off the power to all of the power points in my home. Blew a fuse. Valuable lesson learnt there.
Now I have a proper power supply where I can regulate the voltage and it makes Potassium chlorate quite well with a Carbon anode, it's a good idea to make lots of chloride solution and keep topping your cell up as it gets quite hot, the water evaporates and your anode corrodes a lot, the chloride is used up and there is a lot more resistance in the electrolyte which adds to the heat...

12v, 10A works great. from memory the ratio of potassium chloride to water was about 1:4.

As I said you are best to keep topping up your cell, once about 1/2 to 3/4 of the chloride has been converted the current slows down and the solution starts to boil, if you were to run your cell with refilling to keep it at 10A for 48 hours you would get heaps of potassium chlorate.

Oops went way off topic into chlorates there, sorry! :P

[Edited on 6-3-2011 by trezza]
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Arthur Dent
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[*] posted on 6-3-2011 at 06:54


@ woelen

Whoops! Actually, I just noticed there isn't a brown wire in my power supply! Here's the pinout I have:



So I guess there's no 3.3V sense wire in this supply. All other wires seem the same according to your instructions on your site. as I mentioned, it's an early 20-pin PS, I like it because the case is bigger than normal and so is the fan.

Robert




[Edited on 6-3-2011 by Arthur Dent]




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smaerd
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[*] posted on 6-3-2011 at 09:23


Quote: Originally posted by Regolith  
It sounds however like it's pretty stock still ? No modifications to the power sections, as in it's still wired for its factory voltages and regulators ?


Yea regolith I did nothing to the wires I just soldered them onto the binding posts. Is that bad news? I don't want to fry out the circuits in my house. I just wasn't sure where to even put the 10ohm 10watt resister in the circuit or if it was even necessary.

@peach yea I decided bringing it to school wouldn't be a good idea. People would probably think I'm nuts or something. I'll just buy a volt meter one day when I can afford it lol.

[Edited on 6-3-2011 by smaerd]
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woelen
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[*] posted on 6-3-2011 at 10:01


Quote: Originally posted by Arthur Dent  
@ woelen

Whoops! Actually, I just noticed there isn't a brown wire in my power supply! Here's the pinout I have:



So I guess there's no 3.3V sense wire in this supply. All other wires seem the same according to your instructions on your site. as I mentioned, it's an early 20-pin PS, I like it because the case is bigger than normal and so is the fan.

Robert




[Edited on 6-3-2011 by Arthur Dent]

This is fairly common in older supplies. Actually, there is a 3.3V sense, but it is inside the case. This is not as good as external sense, because voltage drop along the orange wires is not in the feedback loop.




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Arthur Dent
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[*] posted on 6-3-2011 at 11:10


Quote: Originally posted by smaerd  
I'll just buy a volt meter one day when I can afford it lol.

[Edited on 6-3-2011 by smaerd]


You can afford it right now if you can spare ten bucks!

Cheap chinese multimeter

I buy often from these guys, they're not very fast and a lot of their stuff is not the highest quality, but you just can't beat the prices and the shipping is free!

Robert
Edit: Oh and you should see their electronics tool selection, pretty nice stuff, like ultrafine tweezers, trimmers, ethernet cable testers, solder paste etc...

[Edited on 6-3-2011 by Arthur Dent]




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peach
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[*] posted on 6-3-2011 at 12:33


I'd still ask in school. Even if they say no it shows you're interested in science outside of the building, which may please someone. The supply qualifies as low voltage, which might be a good phrase to work into the first sentence.

Regolith, those pens are neat. I've seen the electro stampers and vibrating pin / rotating burr based scribes, but don't remember seeing one of those in action before (there's some guys on youtube showing them, one made from an ATX supply funnily enough).

Re: the multimeter, I agree with Robert. Get a cheap one. It'll do for the vast majority of what you're up to, if not all of it. That one Robert linked to has the luxury feature of direct current measurement, which my cheap one doesn't. I needed to do a few years worth of reading before I started to understand the more complex circuits that need things like oscilloscopes.

This was the site I read by far the most of. It's a naval training manual for electronics; complete and for free. Do not let the amateur appearance of the site fool you, the manual it's self is awesome.

[Edited on 6-3-2011 by peach]




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smaerd
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[*] posted on 22-3-2011 at 13:24


Figure I kind of owe it to you guys to at least upload a picture of the working apparatus(now that the camera is back). Works great just need to find/afford some better electrodes then pencil graphite(erodes way to quickly), etc. They eroded too quick before a test KClO3 electrolysis could complete, but the water does smell nice and mm mm chlorinated heh. One day I'll have the cash to experiment.

DSCF0046.JPG - 93kB

[Edited on 22-3-2011 by smaerd]
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