Question on m2-atx 5v rail to power USB hub...

**vwgtipowr** · 01-31-2006, 02:44 PM

I plan on using on mounting a 4 port USB hub into my dash/glovebox area.
I will also be buying a m2-atx power supply for the car-pc I am building. I have been doing extensive research over the last few weeks.

One question I cannot find an answer to is:
Since I am planning on having the powered hub in the dash, and mounting the PC in the trunck (with the power supply) is it feasibly to run the 5v power from the power supply to the hub (prob close to 15', at least 10' once the wires are routed out of site). Will I see dramatic power drop off over that distance?

The hubs I have been looking at are 5v 2.6-3amp.
I would also have to do the same to run the touch screen most likely.

I am still in the planning/research stages, but if someone could help out here that would be great. I have picked through the search for a while and came up with nothing useful.

Yes, I'm a newbie to this site, so get your shots in if you want.

Edit: Here is some more info on my setup (so far)
P3 500Mhz
256MB RAM (2x128MB modules)
Ausus MB w/On board sound/lan/video
40GB 5400 2.5" laptop drive
Floppy drive (getting removed)
CDrom (getting removed most likely)
Maybe 1 or 2 PCI cards.

The power supply should be more than enough on the 12v Rail, it is the 5v rail that might not be enough since I will be running numerous USB devices (laptop drive, LCD touchscreen, HUB, phone data cable for internet/charge, DVD-rom drive, and maybe USB fm tuner).

**strohj** · 01-31-2006, 04:19 PM

just make sure the wires you are running are thick enough to handle the load...

**vwgtipowr** · 01-31-2006, 04:34 PM

Originally Posted by strohj

just make sure the wires you are running are thick enough to handle the load...

Is there any basic rule of thumb on calculating resistance over distance to determine what guage wire to use?

**Wiredwrx** · 01-31-2006, 05:19 PM

Originally Posted by vwgtipowr

Is there any basic rule of thumb on calculating resistance over distance to determine what guage wire to use?

Ya, there is.

FAQ: Connecting your Car PC's Power and Speakers

Why am I being nice, can someone please tell me.

Michael

Oh, BTW, it is in the FAQ section.

**vwgtipowr** · 02-01-2006, 08:31 AM

Originally Posted by Wiredwrx

Why am I being nice, can someone please tell me.

Michael

Because you are a nice guy.

My searches didn't turn anything up, I must have used the wrong key words.

I would post the chart here, but it is in HTML format.
Distances are quite a bit longer than I expected.

**01black_ac** · 02-01-2006, 03:51 PM

You might find this of interest. I've been considering this USB hub for my own dashboard mount. It's nice and tiny, and you can see the spec-listing on the side shows it only draws 2.1Amps on the 5v rail. Plus, for a limited time it's only $10.
http://www.compusa.com/products/prod...ct_code=310730

'01

[edited to clean up the link]

**strohj** · 02-01-2006, 03:57 PM

hmmm interesting...

**01black_ac** · 02-01-2006, 04:04 PM

<offtopic>
strohj, how do you like the Rikaline 6010 GPS? I've used mine for a while with a laptop, and I think it's pretty good, especially considering I got it for only about $30 on ebay. I've been using mine with MS Streets/Trips '05, but not sure what GPS app I'll use in the car system though.

Have you tried mounting the 6010 under the rear shelf of the car (in the trunk), between the rear speakers? I think I want to keep my GPS located in the rear of the car, since it will be much easier to swap it out for a new model somewhere down the line, but I'm wondering how responsive a GPS of this type is if it doesn't have direct sight to the sky...
</offtopic>

'01

**strohj** · 02-01-2006, 04:07 PM

I love it.. its very accurate.. and fast to grab onto the satellites...

I use mapmonkey for navigation in my truck... oh and I have it mounted underneath the dash in the front.. I get anywhere from 6-12 satellites at all times

**RawsonDR** · 02-01-2006, 09:09 PM

Originally Posted by 01black_ac

You might find this of interest. I've been considering this USB hub for my own dashboard mount. It's nice and tiny, and you can see the spec-listing on the side shows it only draws 2.1Amps on the 5v rail. Plus, for a limited time it's only $10.

USB is spec'd at 500mA. 4x500mA = 2amps, so that explains the power rating. It's not going to draw nearly anything on its own - it's just a worst case number. I don't think extraneous power draw would be an issue for any USB hub.