Power Supply - 12V/5V (2A)

Does your project need a little more umph than our wall wart adapters can supply? Why not give this a shot? This 2A "laptop brick" supply outputs both 5V and 12VDC and is terminated with a 4-pin Molex connector.

The Molex connector is a standard 8981 Series Power Connector, like the disk drive connectors in your PC. Adapters and Cable assemblies are easy to come by at computer supply stores (also, check our related items) so you shouldn't have any trouble getting your project powered up.

To plug the brick into the wall you'll need an IEC C13 cable. You know, the AC cable from your computer or your guitar amp, don't worry we sell them too, check the related items.

The mating connector is part #: WM6988-ND. We don't sell it but it's commonly found.

Note: Only the pin next to 5V is grounded. The pin next to 12V is not connected (NC). Please refer to the picture of the bottom of the unit for more information. Also the AC cable isn't included in case you have one laying around or you're outside the US and will need a different mains plug.

  • Input Voltage: 100 to 240VAC @ 50-60Hz
  • Output Voltage: 12V / 5V
  • Output Current: 2A
  • Output Power: 34 Watts
  • Input Connector: IEC C14
  • Output Connector: Molex 8981

Power Supply - 12V/5V (2A) Product Help and Resources

Building a Safe Cracking Robot

March 29, 2017

How to crack an unknown safe in under an hour.

12V/5V Power Supply Hookup Guide

May 10, 2018

In this tutorial, we will replace the 12V/5V (2A) power supply's molex connector with two male barrel jacks adapters.

ATX Power Connector (4-Pin) Breakout Hookup Guide

October 10, 2019

Do you need to power a project with 12V and 5V from one wall adapter? The ATX power connector breaks out the standard 4-pin computer peripheral port for your 12V and 5V devices!

Output Molex Connector

We recommend using this power supply with the right angle Molex connector](https://www.sparkfun.com/products/15700) and the [ATX breakout board]9https://www.sparkfun.com/products/15035) to easily connect to the pins. Otherwise, you will need to hack the cable and splice wires.

Unfortunately, we do not sell the Molex connector [ vertical in our catalog anymore. You would need to go to Digi-Key, Mouser, or Newark for this option.

Output Terminal Block Adapter

You can try using a terminal block [ https://www.sparkfun.com/products/13061 ] or 2x male DC Barrel Jack Adapters https://www.sparkfun.com/products/10287 for the laptop power supply's output. If you are using both 12V and 5V, you may need to strip some wire and connect the GND pins together. Also, make sure that the wire that you are using can handle the amperage [ https://learn.sparkfun.com/tutorials/working-with-wire#wire-thickness ].

Terminal Block Adapters

Three Prong Power Cable for US Wall Outlet

The power cable [ https://www.sparkfun.com/products/11299 ] for a US wall outlet is sold separately.


Looking for answers to technical questions?

We welcome your comments and suggestions below. However, if you are looking for solutions to technical questions please see our Technical Assistance page.

  • WheelerSounds / about 7 years ago / 1

    I cut off the Molex and grabbed a multimeter, and the wires are as follows: Red: +12V Black: +5V Yellow: GND Please correct me if this isn't the case normally!

  • Never buy this. Voltage drops from 5V to 3.5V under less than 1A load. Bought two of these, going to throw away both.

  • Member #27774 / about 10 years ago / 2

    DOA. Shoulda paid attention to other comments.

  • I can see how these would burn out disk drives. The rails have to be load balanced in order to maintain the voltage regulation. If they're not, the voltages go way out of spec. So it'd be real easy to brown out or overdrive whatever it's plugged into.

    Cracking one open, it looks pretty decent inside. It's fully isolated and has the usual safety protection circuitry. There are two big heat sinks that run along the sides of the case, so it would be normal for the case to get pretty hot. It's not waterproof so it's only for dry environment use.

  • Ty J. / about 12 years ago / 2

    Be forewarned. I've used these at work; they came in the box with some USB to IDE/SATA adapters. We ended up throwing away all of them after they fried two disk drives. (15K SAS disks rated at 1.7A 12/5V) These bricks get scorching hot around 1.5A on both rails. Notice there is a distinct lack of certifications like UL and TUV.

    • steven6282 / about 12 years ago / 1

      I'm really curious how these supplies fry disk drives? Is the voltage regulator in them letting more than 12v of power through?

      I've got the same exact brick that I bought off newegg with a HDD to USB adapter kit and I've used it on many disks without ever having a problem. I'm now needing 12v ~1A for a project I'm working on and the 5V rail is convenient cause another part of my project needs 5v / 3.3v mixed. So I was thinking about using the brick that I got from newegg for it, but I've never used it for extended periods to see the downsides and would rather not see my entire project go up in smoke once I have it in place permanently.

      If it's just a matter of voltage regulation I'll just be sure to put some extra voltage regulators in my project and maybe some fuses as well to protect from surges.

      • Member #45741 / about 12 years ago / 1

        I don't believe the issue is regulation, it would seem the China brands use a cheap version of filter capacitor. I've had one just like this fail that was powering an ext h.d. after being on for 24/7 for about a year. The output caps fail causing poorly filtered DC on the outputs. If you are lucky, the ext HD and board just stop working when the supply fails. If you intend to keep these powered up 24/7, the caps can be replaced with far better ones if you are up to cracking the case open to reveal the parts. Caps would cost about $5.00 from Digikey. Search Lacie supply on youtube for instructions that show how this is done with similar supply.

  • Member #260321 / about 12 years ago / 2

    How good is the regulation on this brick?

  • Member #592619 / about 10 years ago / 1

    Cannot see what the problem is - apart from being nice to look at - dual 0-15v was about £8 at 4 amps - more than enough 7812 / 7805 parralleled , plus a few capacitors and a ramp up circuit to save on in-rush current - probably what fried the disk drives . Apart from looking a little tatty

  • Lil Dutchie / about 10 years ago / 1

    My multimeter measured 6.5 amps output on this guy - and there was a mysterious buzz coming from it. Anyone else observed this?

  • Stuart_F / about 11 years ago / 1

    After reading the comments on here, I planned to replace the filter capacitors per Tim's suggestion. That turned out to be a better decision than I had originally thought. Once I opened the supply up (and prior to plugging it in for the first time), I discovered the 12V rail filter capacitor (1000uF, 16V) was already popped. According to Tim, when the power supply is left connected to the mains supply with no load, the 12V rail can rise to 18V and the 5V can go to 8V on a 250V main supply (he's from Australia). These are over the rated voltage for the 12V filter capacitor (probably explaining why it was blown when I got it) and close to the rated voltage of the 5V filter capacitor (1000uF, 10V) respectively. To cover my bases, I'm replacing both with capacitors rated for 25V before I ever plug it in. I'll try to give an update once they arrive and I get them swapped out.

  • Mine works and I love it, so I bought another. It's hooked up like as shown on this forum post. Oh no, maybe it works because I'm feeding it to Arduino stuff with voltage regulators? I think I'm lucky because I didn't confuse the 4 pin molex with "oh use this instead of the PSU in a computer", rather as "oh goody, I can chop wires of computer crap and use this to power my Arduino project!"

    Thanks to all the hate on here, I'll see what I can do to kill the 2nd one I just bought (because I'm so happy with the 1st one).

    PS - I just created a CAD drawing of this; it's on GrabCAD

  • Member #105105 / about 11 years ago * / 1

    I'd avoid these for applications with sensitive inputs. I totally agree with above comments on output load balancing - I fried TWO Raspberry Pi Model Bs in the span of 30 minutes with this power supply = NOT HAPPY!!! Also, if you hack apart the cord, you'll find the wire color coding is anything but standard!

  • REDACTED-GDPR / about 11 years ago / 1

    Is there any chance you will be offering a 4-5A version? Thanks!

  • Member #423149 / about 11 years ago / 1

    Mine "popped" within the first 2 minutes of using it. I was only powering a small experiment board using maybe 100 mA. These would be supremely handy if it didn't destroy itself. I live in Europe, it would cost more to send it back than to find another solution.

    • I know your comment is a bit old, but have you contacted customer service? This shouldn't have happened.

  • CF / about 12 years ago / 1

    I'm needing to replace the supply on my USB backup drive. This would do nicely. My only concern is how is the quality? I don't want to fry my backup disk. Gota be careful with something that's powered 24/7 and unsupervised.

  • Member #364047 / about 12 years ago / 1

    works like a charm. The diagram is outdated though so you'll need to test all the wires to see which is 12, 5v, and ground

  • JRiggles / about 12 years ago / 1

    Will this supply enough current to comfortably power a project using the thermal printer you guys sell?

  • Member #278726 / about 12 years ago / 1

    wait, If I use 2 of these in parallel will it provide 4 amps?

  • marciomaiajr / about 12 years ago / 1

    Very good idea. 2A is more than enough for most projects. I'd rather buy one of these than messing up with the computer's power supply.

    • That's actually what caused us to look into these. I was driving some LED strips from the MOSFET shield and the ATX power supply was pretty cumbersome and WAY more power than I needed. So these are what we found (a lot more compact). Now I just have to find time to rev the MOSFET shield...

  • J.R. / about 12 years ago / 1

    Possible typo? 12V*2A = 24 W, not 34

    • Member #112321 / about 12 years ago * / 5

      12V2A = 24 W, 5V2A = 10 W, 24 W + 10 W = 34 W

      Thats my guess.

  • Member #304648 / about 12 years ago / 1

    Did your product sourcing amigo do any quality inspection of this device? I have learned to be weary of cheap chargers and other such stuff from China.

    • I buy and resell stuff from China because it's better quality than stuff available to resell that's made in USA. Even wires, which disappointed the patriot in me.

  • Member #278726 / about 12 years ago / 1

    I like this. keep getting bigger ones, I wouldn't mind a power supply that can give out 5,9, and 12 volts or 5 amps.

  • tld / about 12 years ago / 1

    Might be worth noting that while "Molex Connector Pinout" shows both center-pins as ground, only one of them is actually ground in this PSU.

Customer Reviews

3 out of 5

Based on 5 ratings:

Currently viewing all customer reviews.

1 of 1 found this helpful:

Dont buy

30ma load and 5v supply dropped to 4.1 volts Didnt try 12 v as 5 v was power for PI and it choked

That seems odd, and very out of spec. I would suggest contacting our tech support team, they should be able to help resolve the issue.

0 of 1 found this helpful:

Works great

Meets my needs but I'm not pulling much current. I just needed 5 and 12 volts in my project. I would have given 5 stars if it wasn't for the short cord.

0 of 8 found this helpful:

I originally was going to comment that this was "OK", but that it was yet another Sparkfun product lacking a power cord and that I was disappointed. Then the Review title couldn't be changed from "Best Thing I ever Owned!", so I'm downgrading it to "Bad". I probably won't use them because it is more trouble than it is worth to search around in dark corners for unused power cords and I feel suckered and probably won't use them

It works, unlike other vendor's cheaper versions

Bought a one from a Chinese supplier that was rated to deliver 2A at 12v/5v - cheaper, but it was junk, shorted out at about 1A. this works great, and as labeled and rated. thanks Sparkfun, a quality supplier.

Isolating a power issue

Perfect for isolating power related issues on a complex repair