I have a D-Link 7 port USB 2.0 hub model DUB-H7

The hub has a AC power supply that came with it, 5v 3amp output.

Problem, the hub will not supply 5v power to the 7 ports unless it is connected to a PC that is powered up and running an OS, regardless if the AC adapter is connected or not. I belive this is by design.

What I want to do is use this in a automobile to power some of my usb devices, but not have it connected to a PC. I have a power inverter in the vehicle to supply the 110v for the d-link ac power supply.

Not knowing how D-link designed the circuit board, it there some fundamental usb hub design that causes this behavior.

I did some reading on this page, but know just enough about USB electronics to get into trouble and let some smoke out, is there a way to make a usb dongle to fool the d-link into believing it is connected to a PC?

  • 2
    \$\begingroup\$ What's a USB hub without being connected to a host? A USB charger? There are probably easier ways to make a USB charger than using a USB hub. youtube.com/watch?v=4MJAPv3iIAc \$\endgroup\$
    – kenny
    Jun 10, 2012 at 18:45
  • \$\begingroup\$ Just working with what I have on hand, yes a usb charger. It has a nice enclosure, in the end I guess I could gut it and make my own board to fit or modify the one that is in it, but more interested in fooling this one into working by making a usb dongle if possible. \$\endgroup\$
    – Moab
    Jun 11, 2012 at 3:19
  • \$\begingroup\$ Try connecting multiple hubs to each other... you'll get some interesting results :p \$\endgroup\$
    – Daniel Li
    Aug 29, 2012 at 15:24

2 Answers 2


I suggest you simple supply 5V with a suitable current limit to the ground and power lines of your USB gadet. A simple 7805 will do fine. There are numerous designs and commercial gadgets (battery powered, wall-wart powered, cigarette plug powered, some even solar panel powered - I doubt they are effective) that do something like this this. Some links:

  • 2
    \$\begingroup\$ Wouter, you're probably a good guy, but how I would love to see that links in-line! :-). Ah, what the heck, I'll do it myself. \$\endgroup\$
    – stevenvh
    Jun 10, 2012 at 18:53
  • 1
    \$\begingroup\$ i've done 7805 version for myself, by putting through 0.5A it's near it's limits and is hot as hell. I'm not sure about voltage spikes from generator - i was doing it for myself strictly for engine-off mode. What overvoltage protection could be added to a plot? \$\endgroup\$
    – miceuz
    Jun 10, 2012 at 23:06
  • \$\begingroup\$ Thanks, more interested in making a usb dongle to make what I have on hand work. Thanks for the alternative idea's though, but would need 5 or more usb ports for charging/operation purposes and be able to power from my 110v inverter or +12v car battery. \$\endgroup\$
    – Moab
    Jun 11, 2012 at 3:24
  • \$\begingroup\$ I think it may have something to do with adding pull up resistors on the data lines, but have no clue what that means. \$\endgroup\$
    – Moab
    Jun 11, 2012 at 3:33
  • \$\begingroup\$ @Moab: I think what you want is much more work, but its your party... I guess there will be a connection between the hub chip and the pass P-FETs, you could cut that and connect it to ground, or even short the FETs with 1A polyfuses. \$\endgroup\$ Jun 11, 2012 at 6:09

This CAN be done. Turns out that the D-Link uses the reference design for the chipset it uses. The guys I used to work with went in and modified these by cutting a jumper and the hub was then powered without host being connected.

You can see that they guys built a 49 port hub for me, with all 49 ports being able to charge without computer.


Sorry I can't provide you with the exact jumper, but if you can find someone who can open it up for you and cut a jumper, I dont think there are that many inside.


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