how to power USB HUB - tutorial needed

**sly** · 04-01-2008, 06:05 PM

hello,

I'm trying to figure out how to power an usb hub. I found some post concerning this subject but they were not very helpful. Can I power it direct from psu? If so will I need that ac-dc adapter which cames with hub? Is there any tutorial or maybe any thread with photos showing which wires where to hook up?
Is Hub power consumption always constant or maybe it may be vary and depends on how many devices are connected?

**pir8radio** · 04-02-2008, 01:08 PM

if you are not using a laptop you can use the internal power supply to power your hub. You do not need the ac to dc power supply that comes with the hub. You would use the red and black wires in the case (the red black and yellow that runs to drives).

**DarquePervert** · 04-02-2008, 07:47 PM

Originally Posted by sly

Can I power it direct from psu?

Yes, in most cases.
Most USB hubs use 5v power and have a wall-wort type of plug that reduces transforms the power from AC to DC and reduces it to 5v.
CHECK THE POWER RATING OF THE TRANSFORMER FOR YOUR USB HUB TO CONFIRM THIS!!!!
If it draws 5v, basically you wire the power connector for the USB hub into a HDD power connector using the red (5v) and black (ground) wires on the HDD connector.

**Henk Bos** · 04-03-2008, 06:43 AM

I have one in my car and take power of the power supply of the PC (5V).
Most power supplies for Car PCs come with this low volt lead.

**rgarjr** · 04-03-2008, 04:11 PM

U can also use some Point of Loads the store sells to power up your hub network.

**sly** · 04-04-2008, 12:36 PM

ok, thanks. i will try

**FordNoMore** · 04-04-2008, 11:08 PM

You know the various USB vehicle (cigarette lighter) power adapters available for like $10? Any reason one of those couldn't just be hard-wired to a USB hub? Seems straightforward, but I haven't heard of anyone doing that. Are they underpowered?

**quantum** · 04-04-2008, 11:50 PM

Originally Posted by FordNoMore

You know the various USB vehicle (cigarette lighter) power adapters available for like $10? Any reason one of those couldn't just be hard-wired to a USB hub? Seems straightforward, but I haven't heard of anyone doing that. Are they underpowered?

That's is what I did, with a selectable voltage reducer/regulator I picked up at Radio Shack. It has 12v in (cig lighter plug) and a switch for 1.5v, 3v, 4.5v, 6v, 9v, 12v and was like 10 bucks. I just went to find it on their site, but didn't see it. Bought mine in the store.

I set it to 4.5v and got an adapter that fit the hub. It worked fine, and I know it worked because if I tried to plug my slim USB DVD drive into the hub without it, nothing was recognized. As soon as the hub got power it showed up as an external drive, played he DVD, etc.

**piotrg0** · 05-04-2008, 05:24 AM

Hello, I have similar questian about powering usb hub. I bought 5V 2A cigarette lighter power adapter. It has adapter that fit the hub. So almost everythink perfect, but one more question and please give an anwser.

I connected my hub to computer with usb cable, I start up my carpc. Than I connect power adapter to the hub (only to hub, not to cig plug). And I saw that green light on power adapter is switch on. So, my power adapter has 5V from mine usb hub. I check this with voltmeter. I don't know why by power adapter is "bi-directional", is it normal? Can I connect to cig plug? I'm afraid that in some cases my car could try to get 12V from my power adapter, so it means 5V and many many amps from usb hub, which is connected also to carputer.

Should I buy some special power adapter? Or maybe I should change someting in hub?