Not enough power to USB devices >> Possible Solution?

**Jahntassa** · 10-30-2005, 03:21 PM

I think the amperage draw from the usb hub is regulated as part of the way the hub works. Even if you do run the 5v line down the USB line to the hub, the hub will still 'think' it's in 'bus-powered' mode and automatically limit itself to 100mA. You really need to have 5v going seperately into the unit's power input, and either switch it to 'self-powered' mode, or some hubs will automatically determine which mode to run in.

Just because you're supplying more power down the USB cable doesn't mean the hub will switch itself to self-power mode. It has no idea where the 5v is coming from on the USB cable itself, and can't automatically know it can use more amperage through it.

**Tuckie** · 10-30-2005, 04:29 PM

I'll probably have to crack open the hub either way, it has a really small barrel jack, so I would probably just wire my own connector. I think I will try the modified connector to see if it works, but if it does indeed limit the amps through the hub, would it be worth it to just add two jumpers to make it appear that the 5v is comming from the barrel jack, when in actuality its comming from the usb wire?

**Jahntassa** · 10-30-2005, 06:22 PM

That would probably work!

If you don't mind ripping open and modifying the hub..and as you've already modified the cable feeding it...jumpering it so you feed 5v to both the USB port and the barrel jack would work.

I think you still need to feed 5v into the USB port on the hub.. don't know for sure, but wouldn't hurt. As long as you also feed 5v to the power plug on the hub, it should work.

**Sham-Mobile** · 10-31-2005, 12:26 PM

I'm currently using the Carnetix 5v POL to power my USB hub, and a seperate one to power a slim slot load DVD drive/CDRW. Hub needs max of 3.8 amps (7 port Belkin hub), and the DVD drive needs 2amps. Almost done wiring it all up, just need to get wires cleaned up, and install it, should be done in a week.

Also, emailing Carnetix works too, I had an email going back and forth with a guy named Mike there, and he aswered all my emails back within about 4 hours. Gave me complete answers, and helped solve my unsureness.

**Peoples** · 11-01-2005, 10:20 PM

damn....i was hoping i could power my hub & my cd-drive with 1 POL. Have you tried this?

**thanatos106** · 11-01-2005, 10:40 PM

know I said it before but here comes a pic of the SD 25A 5 from measn well.

It handles my 4 port USB hub and the panasonic slim load without sweating!

Thanatos.

**roadhog** · 11-02-2005, 06:06 AM

@ Tuckie
I would check out the gauge of the +5 and -gnd wires in the usb cable. I would imagine that they're only rated to carry 500mA and should you try to carry up to 2.5A they may burn out.
A nice idea in theory, but I strongly suggest that you run two seperate wires from the PSU to the Hub power jack.

**Frankino** · 11-05-2005, 07:55 AM

Tuckie, did you do your wiring trick? did it work? I was thinking to do the same think to avoid wiring? give me a go-nogo please

**Tuckie** · 11-14-2005, 09:01 PM

So far have have yet to hack up the hub to change the power method, but I did give it a shot with just the changed 5v line going into and its still a no-go

**Grey** · 11-15-2005, 06:19 PM

Roadhog is right. I am not sure where your PC is in relation to your hub, but any length of run with modified power going through that under-rated wire is going to be a sure-fire* way to destroy something important to you (pun intended).