Powering USB Hub

**B|ade** · 07-11-2006, 07:35 PM

Hey guys,

I realise this has been covered before but I couldn't really find any definitive answers on it so I just wanted to see what everyone's doing.

Basically, I'm looking for a way to power my USB Hub. I bought one of the Opus Vehicle Point Of Load DC-DC Converters so I have the option to hook it up to that. These are the only questions that I couldn't find definitive answers to:

1. I'd assume the best way of powering it is by using this power supply. The only questions I have is that is there a way to integrate this board with the m2-atx? I know that it's possible to wire a remote/trigger off the 15w PSU. I was just wondering where I would splice this into the wiring of the m2-atx? Can it just be spliced into the ignition wire that triggers the m2-atx? The only reason I'm asking this is that I want it to turn on at the same time that the computer itself is powered on (that way I won't have any issues with detecting new usb devices, etc.). Would I need to place a switch inline to power it this way? Alternatively, could I just splice into the amplifier enable wire to turn it on? I don't think there would be enough voltage in this situation however.

2. I guess the other question I have is that if I wire it up totally independently of the m2-atx, will it power itself on as soon as the computer turns on? What I mean, is that, when the device detects the computer is on, does it power itself on automatically? This has been something I've been trying to figure out for awhile and isn't something I can really test at home (I don't have enough knowledge about electronics, etc.)

Anyway, any help would be great. Sorry for all the newb questions - I'm still trying to get my knowledge up in terms of in-car electronics and how it all works.

**piabu** · 07-11-2006, 07:46 PM

Why not just splice/split the ACC line to power on both the M2-ATX and Opus POL when the ACC (ignition) turns on?

I am not sure about the Opus but the M2-ATX has a 4 second delay to wait for the power to stabilise before it will send the turn-on pulse to the computer. By this time the USB hub should be all powered up by the Opus POL.

You should be able to provide 5v power to USB devices from one source (Opus) and have the data lines connected to the computer powered by another source (M2-ATX). That is definitely feasible.

But if your system is not that power-hungry, you can try to simplify things and have the M2-ATX power the hub from the 5v line as well.

**B|ade** · 07-11-2006, 08:40 PM

Piabu, I was thinking about just powering both off the m2-atx but i'd rather have ample power all round, that way I won't run into problems when I start upgrading, etc. in the future.

If i wanted to power it off the 5v on the m2-atx, do I just power it off a molex connector (similar to the one I use for powering the hdd?). Sorry man, all this power **** really has me confused.

**piabu** · 07-11-2006, 09:54 PM

Originally Posted by B|ade

If i wanted to power it off the 5v on the m2-atx, do I just power it off a molex connector (similar to the one I use for powering the hdd?). Sorry man, all this power **** really has me confused.

Yes. On the molex red is 5v and black is ground. The yellow is 12v and may fry your USB hub if you plug that in.

If you are using a self-powered USB hub, you will need to cut into the USB cable to identify and connect the power and ground lines to the molex.

**B|ade** · 07-12-2006, 06:08 PM

Cool

Thanks for your help mate.

**sama** · 07-12-2006, 06:39 PM

and make sure if you're powering many/heavy devices from the hub, and it's self-powered, that you don't just use the standard USB wire, the gauge is not big enough. you may need to run more wires.

**SUVputer** · 07-23-2006, 03:19 PM

Does it matter if the 5v/ground wire taken from the m2-atx is about 16feet? from trunk to front/dashboard ?

**FC3S** · 07-23-2006, 04:25 PM

length shouldnt really be an issue, i've read about people going farther than that, so it should be fine, mind you, theres probably a closer ground in the front, so u shouldnt really need to run that one all the way back to the trunk