5V 2A over USB possible?

Post Reply
Polyganz
One Eyed Hopeful
Posts: 8
Joined: Tue Feb 11, 2014 8:05 pm

5V 2A over USB possible?

Post by Polyganz »

Hi everyone

I hope this is the right forum for this question. I got my wireless oculus rift setup almost complete except for one little part. The wireless usb transmitter uses a 5V 2A wall plug and I'm searching for a USB plug to use instead. I got a battery pack with a 5V 2.1A output power which should be enough, correct?

USB specifications on Wikipedia says that only USB 3.1 is able to provide 2A or USB power delivery is able to provide even more then that. On the web I only find wall power adapters, however I would need an USB to H-Type Barrel cable (3.4 mm).

Any ideas where I might find that? I know there is one from Startech but they said its only USB 2.0.

Or do you guys have any other idea how I could power this without access to a wall socket?

Thanks in advance :)

geekmaster
Petrif-Eyed
Posts: 2708
Joined: Sat Sep 01, 2012 10:47 pm

Re: 5V 2A over USB possible?

Post by geekmaster »

Multiple USB jacks with appropriate low loss diodes. Some devices I own came with multiple USB plugs on their cables, for higher total USB power consumption. Or use a battery powered hub that can supply that power, or mod a USB cable to connect a battery to the red and black wires (but only to the device, not the host).

Polyganz
One Eyed Hopeful
Posts: 8
Joined: Tue Feb 11, 2014 8:05 pm

Re: 5V 2A over USB possible?

Post by Polyganz »

Ah I see! Thank you for your help Geekmaster.

I've seen those cables with two USB to one for high power usb power output but I would still have to replace the USB end with a DC barrel.

Do you perhaps know of a tutorial/guide for custom wiring the power of an USB cable? I'm a total noob on this and I don't wanna fry up my devices :)

geekmaster
Petrif-Eyed
Posts: 2708
Joined: Sat Sep 01, 2012 10:47 pm

Re: 5V 2A over USB possible?

Post by geekmaster »

Polyganz wrote:Ah I see! Thank you for your help Geekmaster.

I've seen those cables with two USB to one for high power usb power output but I would still have to replace the USB end with a DC barrel.

Do you perhaps know of a tutorial/guide for custom wiring the power of an USB cable? I'm a total noob on this and I don't wanna fry up my devices :)
I made a USB power splitter cable for my Rift. Those I showed it to said it looks professionally made. I took an appropriate barrel connect with a few inches of wire extending from it, and I slit the side of a mini USB cable a couple of inches from the miniUSB jack to pull out the red and black wires. I stripped a little insulation from the red and black wires such that the metal cannot touch when they are brought back together, and then I soldered the power plug center wire to the USB red wire and the power plug outer wire to the USB black wire. I dabbed contact cement into the split USB cable and around the outside. I also coated the inside of a short piece of power cord insulation split up the side, to be used as an outer protection wrap. After the contact adhesive dried, I wrapped it all together so the outer wrap covered the opening in the USB cable, and then I wrapped that with black sewing thread to keep it all tight with the wrapper seam cleanly held together. I coated it all in cyanoacrylate adhesive (super glue), and when dry I died it black with a black permanent marker.

I will post a photo when I get time.

It works quite well, and modding a USB cable does not void the Rift warranty like the internal Rift power mod posted in the past.

It is very convenient to NOT need to carry an extra power adapter, and to NOT find a place to plug it in in a hotel room (though I learned to carry a 6-outlet switched power strip on my frequent trips).

In your case, you would need to combine two USB cables (or more) to get the extra power. Though probably not used in cheap Chinese USB power combiner cables, I would put a series diode in each power line to isolate them, but be aware that there is some power loss in a diode, so use low power-loss diodes to minimize that.

Some computers can supply a full one ampere (1A) to some USB ports (charging mode), so you may get by with only two USB jacks if you can use those ports to supply your power.

If you are not up to that task, I recommend just getting a powered hub that can source that much current (but a custom USB power cable is smaller and more elegant).

Polyganz
One Eyed Hopeful
Posts: 8
Joined: Tue Feb 11, 2014 8:05 pm

Re: 5V 2A over USB possible?

Post by Polyganz »

geekmaster wrote: Some computers can supply a full one ampere (1A) to some USB ports (charging mode), so you may get by with only two USB jacks if you can use those ports to supply your power.

If you are not up to that task, I recommend just getting a powered hub that can source that much current (but a custom USB power cable is smaller and more elegant).
Ah that doesn't seem all that complicated.

The thing is that I have two battery packs. They both have an 2.1 amp output over USB. I'm assuming this is a powered charging slot. So in theory there should be enough power. Now all I would need to do is find an appropriate DC barrel plug and wire it to the USB or to an USB Y cable.

I can't use any power outlet source because I want the whole thing to be portable.

Post Reply

Return to “General Hardware & Software Technical Support”