1
\$\begingroup\$

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?

\$\endgroup\$
3
  • 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

2
\$\begingroup\$

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:

\$\endgroup\$
7
  • 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
1
\$\begingroup\$

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.

https://blogs.oracle.com/eric/entry/49_port_usb_hub_49

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.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.