Instructables

Convert an ATX Power Supply Into a Regular DC Power Supply!

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Step 9: Updates


Originality

This project is not necessarily original and has been done by many people.

The most "together" project is that of this guy: http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply

There are a multitude of other projects, but I feel mine and his are the best I've seen so far.

Issue of the Resistor

Power supplies need a certain minimum load to work properly. The min. load for mine is around 0.8 amps. Thus if you plan on powering LED's or other such low-power device exclusively, you'll need a resistor to provide a load. Otherwise you will damage the PSU.

A meaty 10-Ohm, 10 watt resistor from Radio Shack is a good choice. Wire it across 12 volt and ground.

-12V and -5V lines

It has been brought to my attention that the -12V and -5 lines are pretty handy for diversifying the voltages this thing can produce. These are the white and blue wires I told you to cut earlier.

Of course, adding them is simple, it's just a matter of getting two extra binding posts and connecting the wires to them. It's just a question of "Do I need these?"

I didn't, all I really needed was the 12V line. But as I said, if you need them, they're easy to install.

UPDATE 12-1-11

Still going strong! This little PSU has been super handy. 
 
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agr00m4 years ago
 The tutorial you posted a link to as a more comprehensive how-to, has you putting a power resistor in it.  What's that for?  It sounds like something you either have to have or completely don't need.
gsnoorky agr00m11 months ago
It's useful for charging well-spent car battery. That heavy usage may draw too much power, invoking shutdown.
Megahurtz4 years ago
Excellent instructable! Will this thing run a 12v cordless dril? I have a brass tumbler I am using with a cordless drill but it's a pain having to switch out the batteries every hour or 2. If so, what posts would you use?
gsnoorky Megahurtz11 months ago
Check the amperage--you can't use an average block rectifier. (Note that LCD/LED monitors, etc. which use blocks don't use many watts--they achieve extraordinary energy efficiency.) Note how much larger block rectifiers are for laptops and their sophisticated batteries.

A related issue: DC power supplies actually prove available which feature 20-pin connectors intended for low-power PC motherboards. Such SFF solutions are intended mainly for 12V batteries from vehicles. (Conceivably, DIYs may achieve terabytes in autos.) These low-power boards can't offer much in the way of video performance, though.
JetBlack12 months ago
I'm planning on doind this one for 12V LED lighting, but I'm not sure if it is indeed necessity of this resistor for the load. I mean, I maybe very wrong, but what I'll do is light my place all with 12V/0.7W power LED. What do you think is right for me to do?
trosa33 years ago
Great instructable! I am a R.C. enthusiast and I have had many problems finding a reliable 12v dc supply for my battery chargers. This really worked out great for me, It only costs a few bucks and like you said almost everyone has a pc power supply laying around.
Jomasdf4 years ago
Great job!

I'm a newb, so yeah,,

I was wondering is its possible to power
http://www.alibaba.com/product-gs/325940621/sound_control_led_light/showimage.html
For example with this, and how would I connect it?

Thanks!
StCanna6 years ago
This is a great instructable and just happen to be trying to figure out how to power a peltier to cool a network cabinet. i was going to buy a 12v 105w transformer for about $8 then, i remembered that i have and old 230w psu that has been sitting under my house for a several years that i can use. i've got lots of Nord TM-127-1.4-8.5mx peltiers (5-15v, up to 8.5a) and picked up some surplus heatsinks with fans to put on both sides. the fans are rated 12v @ 1w and since i'm new to this adhoc engineering i want to ask if you know, should i just hook everything to the 12v posts and see how they run or maybe i need some capacitors/resistors. I'm planning on making this project my first 'ible and any help would be great.
darmic6 years ago
where would you get the output from? im sorry, but im not much of an expert. thanks a lot. Regards. darmic