hacking a nonpowered usb hub to powered

**minghi** · 04-05-2005, 02:25 PM

i have this http://www.acortech.com/.sc/ms/dd/11...20Port%20Clear kind of usb hub. However, it is having trouble supplying enough amps to all the devices.

did anyone hack the hub and give like a 5v 1AMP power to it. I am thinking of a 7805 regulator from the ignition acc wire should do it, right? do i need any other parts otherwise to get the 5v regulated power/?

Thanks

**drait** · 04-06-2005, 11:21 AM

You'd probably also want to put in a cap or two to filter the input and output voltages.

If you need more than 1A the LM123K provides up to 3A @ 5V.

**HoSS** · 04-06-2005, 11:46 AM

It will mean more that just patching the regulator in. Doing that will kill your mobo!
The 5v to the hub currently come from the mobo, if you string another input in you will pass current into your mobo, killing tracks or USB circuitry.

At the least you will need to cut into the supply isolating the new 5v from the mobo, or by using a diode. But i am not sure that that will even work properly because the USB is cleverer than that. The 5v is swicthed on/off by the controller electronics, to correctly power sequence & I am pretty sure there is even over current control, which you may upset.

All in all I would buy a powered hub.

**drait** · 04-06-2005, 12:40 PM

Oh, sorry, didn't realize you wanted to power a non-powered hub. Ignore my previous post.

**minghi** · 04-06-2005, 11:38 PM

Originally Posted by drait

Oh, sorry, didn't realize you wanted to power a non-powered hub. Ignore my previous post.

actually i have a powered usb hub but, i dont want to hack into it, mainly cos it costed me around $30 bucks 1 yr back. i run a printer, scanner, external hard drive which are all supposed to run off a usb port for power too.\\ if i connect these to individual ports, they work g8, but no through a hub. my powered usb hub's light dims and the adapter becomes hottttt very fast

thats the whole reason for my quest.

**HoSS** · 04-07-2005, 04:30 AM

Originally Posted by minghi

actually i have a powered usb hub but,

Ah ok, so it has a (5v?) input connector on it?
In which case it should be easy no?
If you are using a linear regulator watch the dissipation (13v-5v x 1A = 6W)
Can you not tap it off of the PC PSU?