Introduction: ATX Power Supply to Benchtop Power Supply

Picture of ATX Power Supply to Benchtop Power Supply

i would like to start off by saying this is my very first instructable.
This projects was started by me looking for something to do with an old computer i have that is out dated and virtual useless. I saw a few PSU (power supply unit) to bench top power supplies on youtube and decided that this was a good idea.
Planned Uses:
A source of power i may need for future projects the deeper i get into electronic prototyping/engineering/fiddling
a gift for my Dad to replace his older louder bench top supply

*I claim no responcibility for personal property damage or damage of ones person by following this instructable*
Tools Needed:
Screw Driver(Philips), Dremel with abrasion grinding disk, Metal File,Wire Strippers, Soldering iron+solder and stand, EYE PROTECTION

This power supply will have 3.3v,5v,12v,-12v,& Ground, with a well placed illuminated power switch.
Bill Of Materials:Working PSU, 5 banana jack binding posts($3.19 per pair of 2), (optional test/jumper leads $7.49 for a 6 pack, project enclosure 7x5x3" $8.99)

Step 1:

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PSU from the ribbon cable era. i will not be going into spec. details because i feel that there is little to no need. Small differences may exist between different manufactures but for the most part all PSU's are the same

Step 2:

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open your PSU after waiting 10-15 minutes after being plugged into wall. Clean out all dust and computer nastiness

Step 3:

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I apologize for skipping a step but. Grind out hole with Dremel for switch. Place switch into hole

Step 4:

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Grind out spaces for banana plug posts. You do not need to use ventilation grate for mounting for components. This is the only place where i had room internal to mount and wire everything.

Step 5:

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Grind out as many holes as needed. i had planned for a sixth post but i didn't have enough space (six holes, only five posts)

Step 6:

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after all this cutting and grinding i strongly recommend a quick pickup.

Step 7:

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Cut off all pin connectors. in this project i only used wires from the 24 pin connector but if u wanted or needed more binding posts all wires are usable for their ratings.

Step 8:

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install all 5 banana jack binding posts. I would recommend buying 5 of different colors

Step 9:

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Use test jumper cables before soldering or joining anything to make sure everything is wired properly
Solder ground to pin to on the switch and the green wire to pin 1  It is critical that You use a the one and ONLY GREEN cable. The green wire must be in a close circuit for the PSU to create DC electricity.

Step 10:

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Tighten bottom of Banana jack binding posts to appropriate wires.
You could very well solder these wires to bottom of posts but i did not for the possibility of future expansion
Standard Wire color to voltage chart for ATX power supplies:
Red: +5v,13A
Orange: +3.3v, 10A
Yellow:  +12v, 12A
Black:  Ground
Purple:  +5vSB(Stand By), 2A
Grey:  Power Good
Blue:  +12v, 0.8A

Step 11:

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if your psu had protective plastic under boards you NEED to put these plastic sheets back or else u will murder your psu and run the high chance or electrocuting yourself. I needed to cut  this sheet to let the banana binding posts have clearance when plate is put back on unit.

Step 12:

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Reassemble unit and plug in wall power cord. turn on PSU  with switch. If switch does not give any visable apearence that PSu is on use a multimeter to check for dc voltage in posts. if voltage is present i recommend that you make sure that no wires are contacting fan.

I used an illuminated switch so it was more clear whether or not the PSU was creating power. The led light in the switch is wired to a 3.3v or Orange wire for power(light will only illuminate if PSU is creating power to all pins

extra wires should be cut off as far in case as possible
use crimp connectors to join wires and Binding posts

Step 13: Contest Entry

I am entering this constructable into the "make-to-learn youth contest" in hopes of winning a prize to further my knowledge of electronics systems.
What I made:
  I made a benchtop power supply from a Computer ATX PSU (power supply unit)
How I made it:
  I used my knowledge of soldering, computers, switches, and lighting to create a tool that will help me in the future
Where I made it:
  I made this Bench top Power supply in my Fathers garage with the tools that he has
What did i learn:
  I learned that i don't have to but hundred dollar tools when i can make them myself.
  I learned that with basic knowledge of electrical systems you can make a lot happen with what most would consider scrap/trash.
  I learned how wiring in  electronics and houses act very alike
Why i made it:
The main reason i made this is to make my dad who cant be home often due to his job in the military something to make his like a little easier and a little bit more silent


KB0LFL (author)2017-06-04

Would it be possible to have it 13.8 volts? How?

mspencer8 (author)2016-07-08

Hey i just wanna ask i can add another post for a 5volt with a 4amp or 5amp current? Because im gonna use that to charge 18650 batteries..

Is there a possibility to do that?

And also all of 3.3, 5 and 12 volts are all 16 amps, where should solder the brown wire?

My psu is Delta Electronics DPS-220U B-5 A if you wanna check it out..

I really need you held right now man..
russ_hensel (author)2015-01-09

Just a note to let you know I have added this instructable to the collection:
Encyclopedia of ATX to Bench Power Supply Conversion
Take a look at about 70 different approaches to this project.

Gelfling6 (author)2013-06-10

One minor suggestion, if the fan is facing to push air into the supply, it should have enough room (& wire) to reverse to draw air OUT (through) the supply case.. I ran across this quite awhile back, even with an old computer I had, which someone made an add-on cooling fan, but it forced air into the case, keeping it warm.. (Less points to escape from).. But, reversing the flow to draw the air out, the machine ran cooler.

gman1881 (author)Gelfling62013-11-04

that actually makes a ton of sense. may have to crack that bad boy open

astral_mage (author)2013-09-19

i c wat he means by sloppy work man ship

astral_mage (author)2013-09-19

or use a step drill to make correct sized hole?

arkangel1975 (author)2013-04-11

Welcome here!
Good project, good descriptions, look forward to seeing more form you!

gman1881 (author)arkangel19752013-04-15

Thanks! Plan on making a whole lot more for my hobbies. Stay tuned!

pfred2 (author)2013-04-11

What kind of noise does your dad's old power supply make? Like what is making the noise? If it is a fan you can usually quiet those up with some oil. Look under the center hub sticker of the blades for where to access the axle that needs some lubrication.

How come all of your pictures are mirrored? I almost thought you wrapped the wires around your banana jacks the wrong way. I still think you need to get all of your stranded wire under those jack lugs. Try twisting the wire and tinning it lightly with some solder to hold the strands together for you. For that to work good though you have to twist the wire neatly, not put too much solder on it, and bend the end in a hook that goes around the stud.

gman1881 (author)pfred22013-04-15

The old power supplies noise is probably just the fan now that u say that. I did take your advice with soldering the wire tips knowing they are just kind of sloppily in there was starting to bug me. With future instructables I plan on mirroring them to be correct (for perspective) but I didn't realize until u made the comment. Thank you for the constructive comment :)

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