Instructables

ATX Power Supply --> Cheap Bench-Top Power Supply

I've always had a problem with power. For every project, I've been wasting batteries (usually 9V ones, which aren't cheap!), or fuddling with a rat's nest of wall warts. I recently saw this instructable on how to make a cheap power supply out of a computer ATX power supply. So I also headed over to this site for more detailed instructions on how to do it. I took an old Dell E310 desktop, and ripped out the power supply. It gives me 12, 5, and 3.3V DC for use with future project testing, and has a green indicator LED which will turn off in the case of an overcurrent, overheating, or any other related error. The red LED on the switch is simply to indicate it is getting 120V AC power.
I've been having a bugger of a time keeping mine powered on. I have tried putting a load on the 5v and it still powers off after I apply a load to the 12v. I have added power resistors to the 5v and the 3v separately and together and it still shuts off as soon as I load is added to the 12v. What's next?
ubicity2 years ago
very nice
brusho1502 years ago
HI!
Brilliant instructable I am new in electronic engineering and wanted a lab power supply will you please tell me that how Can we add a potetiometer(voltage regulator),rheostat, voltmeter and ammeter to calculate and vary voltage and current?
Thanks
Project D2 years ago
When you say up there that you had to add the transistor "because of the way the switch is wired," what exactly does that mean? My build is using the same switch I picked up from the Shack, so understanding what you mean would help me greatly, especially since I don't want to fry the switch or the LED.
I need some help. I am trying to make one of these and the yellow wire is +12v and my meter reads +9.98V. And the blue wire -12v reads -7v. And the fan is barely spinning. Any help would be appreciated. Thanks in advance.
Your power supply may have a minimum load requirement. Do a search of your ATX power supply on Google and see if the company says anything about it having a "MINIMUM LOAD" value.

If it does, you will need to purchase some Power Resistors. This will trick the power supply in thinking that there is a computer running at the moment and power SHOULD stabilize.

Check out Matthew Beckler's 'able where he makes yet another ATX power supply. Specifically, you should take a look at step 2: http://www.instructables.com/id/ATX--%3E-Lab-Bench-Power-Supply-Conversion/step2/Planning/

Hope it solves your problem. =D
abc123abc4 years ago
how did u find the 12v 5v 3.5v from
theres a specific wire for each voltage
ste54425 years ago
I like it - I have applications for a high current 5V supply but to buy a dedicated 30Amp 5V PSU is quite expensive - the ATX is high current and dirt cheap!

Good work :-)

PCBPolice
hominid5 years ago
Very nice pictures and good inspiration. As the term "Instructables" implies, I feel you need more description (for instruction) and also this article should be in the one spot with no outside links.
Please take these comments constructively and you will shine.
LinuxH4x0r5 years ago
Very nice! What did you do with -12? I find that it can be very useful when you need 24, 17, or 15v. 5/5*