[GUIDE] Making a molex-to-barrel adapter

[jacobsson 218]

Red wire must be center pin on plug (aka a center positive barrel)!

EDIT: The barrel in the image is just an example, choose a barrel with thicker wires than this.

See http://forum.techinferno.com/enclosures-adapters/10090-visual-guide-opening-akitio-thunder-2-pcie-box-powering-via-barrel-plug.html#post134535 for picture guide to do this.

Don't want to solder?

Use this screw terminal variant instead available by searching ebay for "5.5X2.5mm DC Power plug Terminals Connector Adapter Power -female"

<A HREF="http://www.ebay.com/sch/i.html?_odkw=5.5X2.5mm+DC+Power+plug+Terminals+Connector+Adapter+Power&_from=R40|R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.X5.5X2.5mm+DC+Power+plug+Terminals+Connector+Adapter+Power+-female.TRS0&_nkw=5.5X2.5mm+DC+Power+plug+Terminals+Connector+Adapter+Power+-female&_sacat=0"></A>

[linh1987 16]

Actually it's a very simple mod. I have a barrel plug handy so what I did is cut it out, separate the outer and inner wire, twist outer wire with molex's black ground and the inner wire with molex's 12v yellow and that's it. The other 2 wires of (red and black) are unused.

In use the barrel plug is connected to Akitio board, the riser is UNPOWERED. I'm not sure it we should also power the riser but I have it running fine for me up til now (9 hours without any crash).

My barrel plug has a very clear outer/inner wiring so it's a piece of cake. If it's 2 wires setup like above then I recommend you carefully do testing before wire them together

[linh1987 16]

or a premade one like these which you should be able to plug directly to a PCIe connector

Rockminer R Box Power Cable 4 PK 12V PCI E to 3X 5 5mm x 2 5mm DC Barrel Plugs | eBay

[jacobsson 218]

or a premade one like these which you should be able to plug directly to a PCIe connector

Rockminer R Box Power Cable 4 PK 12V PCI E to 3X 5 5mm x 2 5mm DC Barrel Plugs | eBay

The price is not right I min opinion, it seems like they all cost ~$25.

Making your own would probably take you down to ~$5

5.5/2.5mm Barrel

PCIe 6-pin extender

[linh1987 16]

The price is not right I min opinion, it seems like they all cost ~$25.

Making your own would probably take you down to ~$5

5.5/2.5mm Barrel

PCIe 6-pin extender

Yep, it's just an example of what's available out there. And it's 4 set of 3 cables, which can be... handy

[nesone 26]

Hi All,

I make this tutorial on how to build a Molex to Barrel, I'm not an expert but I hope it works!

https://www.youtube.com/watch?v=V4T1DADdKJI

Thanks.

[Dschijn 329]

I got this plug with 0,75mm^2 wire: DC AKS 7525: DC-Kabel, 2 x 0,75 mm, Stecker gerade, 2,5mm bei reichelt elektronik

It is rated to pass 12V / 10A.

[Gmonkey 14]

Hello everyone,

I bought this molex extension to create a molex-barrel adapter, but I'm not sure which cables I have to use. Are the yellow one and the black one next to it? Yellow is 12v and red is 5v, isn't it?

Thanks!

[Dschijn 329]

yellow = 12V

black = ground

red = 5V (not needed)

I would stronlgy recommend you to use more than 1xmolex to power the barrel plug. Better get a 2nd one and combine them.

[Gmonkey 14]

I haven't read that before! Two yellow cables (12V) together in one entrance of the barrel pin and two ground cables to the other entrance? Is that what you are saying?

I have a 500W PSU and I thought to use one pci cable to give power to my graphic card and one molex cable to turn on the Akitio Box.

Thank you for your help! (as usual)

[Dschijn 329]

I haven't read that before! Two yellow cables (12V) together in one entrance of the barrel pin and two ground cables to the other entrance? Is that what you are saying?

Yes! The cables aren't the problem, but (imho) the Molex plug is. The plug isn't made to transfer that much power. If you imgine e.g. the 6-Pin PCIe plug has 3x12V pins and 3x ground pins.

Transfering the same power on a Molex plug with just 1x12V and 1x ground could be risky. So my advise is to spread to load on at least 2xMolex plugs, like the 2xMolex -> 6-Pin PCIe adapters do.

I have a 500W PSU and I thought to use one pci cable to give power to my graphic card and one molex cable to turn on the Akitio Box.

Since you will have more than just one Molex plug... use them!

[Gmonkey 14]

Ok, I understood! I am going to try buying this one (I think I can return my molex extension). EDIT: Now I've seen another one with 3 yellow cables. Is it going to give more stability or it doesn't matter 2 or 3 cables?

Thanks!

[Dschijn 329]

2 should be fine, but 3 might be better

Still… if you are going to use the barrel plug with screw terminals, I can't say if 3 cables will fit.

[protojx 10]

can I leave the other yellow cable detached?

[Dschijn 329]

can I leave the other yellow cable detached?

As long as you are using 2xMolex plugs and 1x yellow wire from each of that plugs you are fine. If there is a 2nd one... just shorten it and make an isolation on its top (or just use this 3rd wire as well).

[Gmonkey 14]

Ok, I am going to try with the 3 yellow cables version. If at the end is impossible to use all the cables I will use two of them. Is not a bad option.

Another question, my PSU has a Type3 cable to three female Molex. Is ok to provide energy? I don't think I am going to need another Type3 cable to separate the two male Molex to Barrel-pin (one per Type3 cable), isn't it?

[Dschijn 329]

should be fine.

[Gmonkey 14]

Well, at the end I bought the cable with three yellow cables but was impossible to introduce more than two inside the adaptor. I used two yellows and two blacks, next to each other, not tangled. The yellow cables inside the positive symbol side, and the black ones in the negative side.

What do you think?

[Dschijn 329]

Looks good!

Just make sure to remove and isolate the unused 3rd wires (they do not fit into the screw terminal anymore?).

[Gmonkey 14]

I tried a couple of times but was impossible to introduce the 3rd wires into the screw terminal. The only solution is to cut a few thin grey wires inside each cable to reduce the volume and have space for all three cables but I think is not a good option. Maybe if the cables have a small quantity of grey thin cables this will give energy problems.

[Gmonkey 14]

Well, I just try to test my adapter molex-barrel and it was impossible. The connector doesn't enter Akitio box. I think the size is incorrect, maybe they gave me a connector with a size 2.1 instead of 2.5.

Has anyone here had problems with this type of connector?

[Dschijn 329]

Well… it has to be the one with 2,5 and 5,5!

[Gmonkey 14]

Hello everyone!

Yesterday I finally received the correct connector (2.5mm) and I could start my molex-barrel test. I tried the Akitio with an USB 3.0 PCIe card and it seems that everything is working properly.

Now the next step is to begin testing the graphic card but I have to wait after Christmas for that.

Thank you for your help!

[Enano 3]

I'm guessing this won't work right? Noob mistake I guess. So, how can i fix it?

[Dschijn 329]

@Enano Seems ok, but I would recommend to make that with two Molex plugs.