How To Convert A Computer Power Supply Into A DC Power Supply 

I appreciate that you consider the project as a longer term one. Most people just hook up the wires with electrical tape but yours is more elegant. I still won't be spending the extra money on this project but you've encouraged me to consider it for the future.

your video is the only video in the world apparently that actually explains how to hookup the switch and it worked beautifully for me thanks a bunch brotha awesome video finally got it working!!!

for a video made in 2012 still getting comments .. really like your video in doing so.. cheers

The switch on the supply, is the MAINS (I.E. it removes ALL AC from the supply). the ATX Green (Pwr-On) is the wire the motherboard toggles for On/Off. Usually have a Yellow LED/resistor off the +5VSB to tell if the supply is live (Mains On).. and use the green wire for control. I imagine you'd give a minor surge switching just by the main, and keeping the Pwr-On wire hard-GND'ed. Also, try unplugging the AC plug, then switching the supply on from the Pwr-On within 15 seconds. Yes, it's stored

Just took apart two big computer towers today and ended up with some spare parts, two of which happen to be these "little" power supply things lol time to get a couple parts and experiment a little

Working on it. I found out I need a 3.3ohm resistor on the 5V circuit to get the yellow one up to 12V. I also soldered a 2.2V LED with a 140ohm resistor to it, between the grey and black one. Hope to have the conversion ready soon... I'll let you know.

Exactly the same as yours. The 12V circuit did not function without any load on the 5V system. So I put one 3.3ohm on the 5V and one on the 3.3V rail as well, since the manual states that a minimum load is required on these 2 rails. Now it delivers a steady 12.2V on the yellow rail....

Thanks for this informative video. As a beginner, I will proceed and hopefully be successful. I do not understand just how CRITICAL some doods are, Adam Novak!

OK im not giving up yet..... Yes I just looked at the link and its very helpful thank you for that info and all your replies.

Thank you anyway man, I got it working in the end, English power supply is shit, so I figured it all out in the end, now getting 10amps through my CB, wouldn't have been able to do it without your video though, thank you :)

Great wee video thanks for explaining how to do that in an easy straight forward way, the work is tidy.

solid video, just what I needed. Keep them coming. Best Matt

Every LED should have a voltage and current rating in its specs. From there, it's application of Ohm's law: I = E / R. The voltage drop across the LED plus the voltage drop across the resistor should equal the voltage you're connecting to. Simplified, R = ( PSV - LEDV ) / LEDI. Plugging in typical values, 5V PSU rail, 2.2V, 10mA LED, ( 5V - 2.2V ) / 0.010A = 280 ohms. Std. value 270 is pretty close, but 300 would be safer. Obviously you could choose a different LED, maybe a 2.2V 15mA one.

Excellent, thanks. One thing - when plugging the fan in I'd have connected the clips to the fan before plugging into the box. You could have shorted the croc clips together by mistake

Just completed this project and I have a couple of observations which may of interest. First, no need to fuss with the black wires at all, chop them all off. Use chassis ground as your negative terminal, I tied my black (negative) binding post output to the chassis directly, no wires at all. This actually results in a slightly higher (0.1v higher) output voltage when load tested. I tested my finished product with a 1.6 amp load. The voltage output at this load is 11.8 volts. Not as good as the wall-wart 3 amp power supply that came with my 12 volt stereo amplifier which holds at 12.3 volts when loaded to 1.6 amps. I will try the project supply with the stereo anyway, just to see what happens. It could happen that the regulation on the computer supply is better than the wall-wart at a higher current loading. Not possible to measure this on audio equipment easily because of transient nature of the audio wave form. If you have read and understood all this so far, give yourself an engineering diploma. hahahahaa

It's best if you find some way to load it first, then turn it on. That's part of the reason there is the POWER_OK wire. So during testing you might want to take something inexpensive/expendible (like that fan you showed) and connect that while switching it on, and maybe do it outside if possible so that if it does go poof it's not going to set anything else on fire. If something is wrong, usually it'll just pop a fuse in the PSU while arcing, or at worst trip your house fuse or breaker.

Thanks for this.. The only vid I found which actually worked for me!

you are very good in teaching am impressed Keep it up sir God bless you m=n your family

a small yet important notice, it's not diode but a resistor u need to use with LED

this is great for people that run mobile cb radios indoors and need a regulated power supply.

yes, exactly! i saw how others did it and did not want to work with so little pace! and wires could melt, short out if so tightly packed

I never cut off the ones not needed I left them connected to the plastic plugs, My dell PSU did not need to use the grey so test to see before you cut the grey wire. I used green&black on a switch. Cut the yellow 12v and black Gound. tested it and worked. I have kept the other 5v and 3v so if in the future I can hook up a USB socket to it for my phone

Correct, a diode is meant to restrict current to one direction of flow.

strip a wire, put the bare wire into the terminal end, then crimp it, crimping is just crushing the metal so it clamps on the wire, takes some effort sometimes

An AT PS can be used. Just use a DMM to test the colored wires to see what the voltages are.

You can use a self made or modified transformer but they will still drop in voltage when loaded. Also you'll still need a big transformer for higher amps. There are 10-15 amp regulated power supplies availeble nowadays. But I expected a 300watt 6 amp psu to handle at least 3 amp at more than 11,0 volts. I'm thinking that i'm possibly doing something wrong.

bought a new pre built pc. used it over 2 years never had problem. one day I decided to slowly upgrade and eventually chuck in beast vid card, so power supply 650w was recommended. so I bought 650w psu, installed it month later started to hear ringing my ears I never heard before.

Well done. Nice presentation.

Thanks for the video, it was very well explained.

Green goes to the ground(Black wires), Brown to the orange, that you have done, Now for the grey wire is the wire that need a load. if you dont have an L.E.D connected to it like i did your system will not turn on. so connect the grey to the positive of anything really that draws power. L.E.D's are the easiest, then connect ground to the negitive of the load.

Thanks for the video corbonzo1, it helped me with my project. I have a FSP300A PSU that I was working with and was trying to put it together like everybody did with the ATX PSU. Needless to say, it wasn't powering up, IN-TILL, I seen your wire configuration and it powered right up after that. Like you said, every PSU is a little different... Thanks again...

Nice job, well understood... may need some help later on i have a few of these im messing with.

Dude you don't need any sensing wires except the green to turn it on. I've been using a setup like this for awhile for my lipo charger and I never needed any of the neg wires. Anybody that wants a higher amp PS thin 17-20A checkout the Dell Poweredge 6650 PS, it's 12v 72A and it doesn't have wires just a plug that you can pick and choose what you need to use. They can also be put together to make 24v.

I thought it was a pretty decent video, well done, another one I have seen a guy put all the terminlas on the metal case itself, yes that should be something like a 1000 ohm resistor not a diode on the led, slip of the tongue no doubt :-) Fred UK.

Finally got my dell PS to work. Now to hook up the posts. I noticed at the end the pos clip fell onto the case. I thought for sure it would short out the PS.

Your tutorial is just fine, calm down :)

this is way more complicated than it needs to be

Thanks for the how to kiddo!

i would most likely add multiple outputs, instead of one ouput, for each voltage. since something like this, is usually made so you can hook up projects, and they might need several outputs, of the same voltage to function. but thats just my thoughts on the project.

I used a little Green L.E.D i dont know much else lol i dont really pay attention to the LED's power input. i couldnt find how much voltage came out of the grey wire. so just to be safe i added a resistor(i apalogize if i had said diode, LOL) so the LED couldnt be burnt out by to much power. and also i dont mind question if you have more feel free to ask me them.

thats a great idea! iv used mine so much and it still hasnt died so thats good, but i like that idea

one end is bare metal, and other end is covered with a plastic . the end with plastic is where the wire goes in and you crimp it

yes, if you connect the outputs in parallel it should work!

Good video keep it on

if u just want to have a 12v power suply all u need is three main wires witch is green wire to the black wire so it would think its on and the yellow wire is the 12v and there u go now u have a 12v power suply thats all u need :)

OK thank you and sorry to bother you with all my questions.

Wow, thanks for that!

Thank you, works great

5:03 thats a resistor not a diode. To the guys who watch this don't do anything with electronics (espacially if it needs mains voltages) if you have o knowlegde of electrical engineering

at first it was not an issue... but as through time using the 12v rail to power my flyback driver. something started happening. voltage would crash and the breaker in the power supply would always go off, it wont stop doing to. Im probably going to scrap my ATX power supply as a housing for an SSTC im preparing to build. I have to MOT cores with their primarys. Ill either make single voltage one for project. like one for 12v with a tone of amps, 50v with less amps. - continued

Thx....also, I am using a PC power supply to run a tennis ball machine...300w is insufficient...can I put two ps in tandem for 600w ??...this I think will allow me to run the ball machine and free me from lugging that heavy battery around....thx!!

Good video :)

yes, parallel is connecting the same colors into one, the power needed might have hurt your ATX's

it wont be purple or blue, those are negative voltages. id say just test :/ i dont know it its the grey or green one. though im sure youd be fine if you just hooked them both up

well I tried the dual power supply idea....the tennis ball machine worked great for about 20 mins and then stopped. The low battery light came on too. I tried tinkering with it but could not get the tennis ball machine going again. Your comment about "outputs in parallel...is that a specific wiring arrangement ?...I simply connected all the yellow and black wires in 2 twisted bundles of wire ...and then attached them to the positive and ground of my ball machine...is this correct?

wouldnt have mattered if i had, not dealing with destructive power lol. and it has a breaker so it doesnt harm the power supply. but good tip for more serious situations

Ok, thanks. I connected the green wire directly to a black wire (I don't need an extra switch), but when I power on the power supply, the fan rotates for maybe a second, then stops. Does the grey wire need to be connected to something as well, or is it only a power good signal? The brown wire is already connected to an orange one in the 10pins plug. I also read that the 5V circuit needs a load of at least 1 Amp in order for the 12V circuit to activate. Did you need that as well?

ok corbonzo1 I have got all my wires sperated and the colors I have are orange, red, black, yellow I have all these zip tyed together. The wires I have left are 1 purple, 1 blue, 1 green and 1 gray. No Brown. The power supply I'm using is a ATX HP 366307-001, which one do I use with the orange wires. Thanks STEVE

Thank you

Ok, thanks. What kind of LED did you use? In the video you talk about a diode, but I guess you mean a resistance? What kind? So no load needed on the 3.3V and 5V rail in order for The 12V to work? Lots of questions... ;)

Get it right in a minute, 1k if it was on 12 volt line, about 300 ohm if its on the 5 volt line...that's better Fred.

Nice video. I have the same power supply and I want to use it as a 12V power supply for a battery charger. Is it correct that the 12V wire, yellow?, can 'deliver' 13A? I want to be able to get as much amps out of it at 12V. Is there a way? Thanks.

do I need to create a load on the red 5v wire to increase the output of 12v on the yellow wire ??

hey sorry scratch that, i was forgetting a bit, use the green and grey how i used them in the video, the fact that you dont have a brown one probably means you dont need one, im hoping

I converted a couple of psu's now now but I found that lot of them have a voltage drop with increasing the current and even though for example 5A is mentioned on the manual it wouldn't do over 2 Amps. What are your findings about that?

i have a blue, brown, white black wires that gone to a switch outside of the computer. i got the PSU separate, i dont however have a green wire. going to the MB. but blue going. would i have to connect the blue and ground?

Hey I got another question if you don't mind? I have the same color wire as you have in this video... I want a light inside of the power supply to come on mostly for looks but to also indicate the power is plugged in but the switch is not turned on. I have this in one of my other ones and when I plugged it in the purple wire was hot even with the switch not turned on yet. So I'm trying to do this to a second power supply but can't figure out what wire I can use because I can't find one that's hot with it just being plugged in. ? Sorry so long hope I didn't confuse you.

Yes, the yellow wires are 12vdc, but to get all the amps (13 Max) you need to connect them all together into one terminal. I hate to ask but i don't have many subscribers... if this video helped, i would greatly appriciate a subscribe.. :)

I'm sorry, but anyone that doesn't know about Radio Shack parts (or can't recognize them immediately upon seeing them, especially in their bags labeled RADIO SHACK) shouldn't be trying to wire up something like this in the first place! LOL!

Continued - or im thinking of having a 120-120v but have cuts in them at curtaint amount of turns so i have a bunch of wires coming out with different voltages all ranging where i want between 0-120. so i basically have a variable transformer with moderate amperage. will this work? i dont know for sure yet. and have to do more research

Dude in my opinion you didn't adopt the easy way to do your power supply. You could just solder the wires directly to the binding posts. And why use two boxes if you can do it in the PSU box?

Thats odd I didn't need to use a 3.3ohm resistor. What model is your Power supply?

The purple wire in this power supply has a Positive Voltage. Hmmm not sure this is a learning experience for me. Now nothing will come on but the LED light by the switch. The fan won't run and I have no power to my binding post. I looked for a fuse but don't see one. You think its a lost cause?

is your switch redundant? You have a switch on the power supply. So if you connect the green wire to one of the black wires the switch on the power supply would be the on off switch. I am making one and don't want to have 2 switches like yours. So would one be redundant?. Nice vid though and very nice looking ps you got there

The purple wire is the only wire getting power because its wired to my LED indicator light and it cones on. I don't have power to nothing else .

You might not even need it, look at the link in the description. I don't really know. You'll have to experiment!

im aware of that. but i never stated im changing ac to dc, so im not wrong, the name of the supply is a DC power supply, its not a change its a name

can i attached red and yellow and orange wires to take maximum amps

One question, why do you need to use all of the wires on each post? Is this to allow you to draw the maximum current on each rail? If this is the case, if you didn't need such high amperage, could you just use one or two of the wires? This would result in a thinner cable running to the project box. Great video though.

i have No brown wire , all i got is red , yellow , black , 2 orange wires and 1 blue , 1 grey , 1 purple , and ofcourse 1 green ... blue 12 v , orange 3.3 , yellow 5 WHAT DO I DO , please answer

What if I do not have a brown wire? Do I use one of the other colored wires?

1000 ohm if it was on the 12 volt line, prob about 300 if it was on 12 volt line Fred.

Power supply's convert ac to dc already, you only created a hub for the 3v 5v and 12v sources. You didn't change it into dc though, it was already dc. You could say, how to make a 12v hub though and that would be correct.

they didnt burn up, the power supply was still in PC and one day the PSU just gave up, fuse was still good

I do not have Green wire all i have is : grey white blue ONE orange andd brown help??

I will try tomorrow and let you know what works.........Thanks for reply

I cant see brown wire in my power supply ? When i commect green and black it takes a jerk and then gets turn off

i have 4 main power wires, blue brown white black. \/\/ (link on next comment) \/\/ do i connect white and blue together, and black and brown together

one power supply works at 100% and the other will pull up the rest of the power, working like this will prematurly kill the first power supply

i cant imagine you doing something wrong, theres not much to it

um i really dont know, im sure it would work if you connected it to your switch already in the suppy

can i hook up a car amp in my house then using this technique?

man, umm I dont know what to do, does your ATX look like mine? look at the link in the discription, that may help you

I have a power supply that had power up to the time I bound all wires to there binding post and tried to test it and nothing works but the LED for the on/off switch?

What do you recommend with these binding post. The first power supply was nickel plated and the power supply that keeps tripping is gold..that's the only difference between the 2 and the first one works fine.

i do not have a brown wire on my power supply. After separating the orange, yellow, black, and red, I am left with gray, purple, blue, and green. On the board the remaining 4 are denoted -12v, +5VFP, PG, and ps_on . Is there a way to tell which wire will act as the brown, according to the way they are labeled?

well, yes you could.. what kind of speakers? because it would be pointless to use this for computer speakers or something that small. instead you could use a wall outlet transformer.

could this be used with a car battery and electrical socket?

how do I get an output of reverse polarity of 12v???

My problem .. I have connected Green wire with one black and The brown(sense) with one orange .. But the power supply is not starting even then .. What should I do now ?