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Thread: USB Hub

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    USB Hub

    I have just bought a Belkin 4 port USB hub as I am getting low on ports on my laptop. A quick experiment caused me to scratch my head. I have a small 64Mb USB memory stick that is used for quick file transfers and I have a larger storage 40 Gb Omega external hard drive.

    If I stick in the USB stick it is seen as Removable storage but if I stick in the 40Gb drive it is not recognised on the hub and I have to plug it into the spare US port in the laptop. This is not a real problem but what defines a hard disc as opposed to temorary storage?
    Jerry

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    Re: USB Hub

    Hey Jerry. Happy New Year. I don't claim to know a lot about this, but the only problem I've had with USB is "powered vs. bus powered." I had a small, 2 port, non-powered USB hub that drew its power from the bus and I couldn't get devices to work on it if they did NOT have their own, separate, power source. I have since bought an AC powered 8-port hub (D-Link) and have both external USB hard drives and several other devices connected with success. One of the devices is a camera memory stick reader that loads OK as three separate drive letters. Is your hub powered with its own AC adapter?
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    Re: USB Hub

    Hi Al

    that is an interesting point, both the 64Mb and the 40Gb are Bus powered. The 64Mb has no problems. I have just added my 233Gb external drive which is powered and it has no problems at all but again places itself under Hard Disc drives.

    The issue then is the 40Gb drive which is not a great problem as I have a spare port on the laptop, my greatest need is the 233Gb as I want to run my Virtuals from there but have access to items on the USB.

    I am having problems with the 40 Gb though where it might have been knocked about just once too many times hence why it acts differently, now if I can only find a 5 volt 1 amp power supply somewhere <img src=/S/hmmn.gif border=0 alt=hmmn width=15 height=15>
    Jerry

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    Re: USB Hub

    Try looking at the properties of the USB Root Hubs in Device Manager, the Power tab will show you how much power has been assigned to each device and may make it clear why you have a problem.

    StuartR

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    Re: USB Hub

    Ahaha well spotted Stuart, it is a long time since I went in to that little recess, how quickly one forgets . It appears each USB on the hub is 500mA and my 40Gb as stated above requires 1 amp. I was doing something in between times and I did think to myself that although the blue LCD was on it was a bit dimmer than normal so that confirms it is a power issue.

    I bought this little baby for work and just didn't want to lug around yet another power supply, I can live with this <img src=/S/cheers.gif border=0 alt=cheers width=30 height=16>
    Jerry

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    Re: USB Hub

    For those looking for a small foot print external USB drive, have a look at this Seagate Drive http://www.seagate.com/products/reta...ble/index.html
    I got one for Christmas and fits in one computer bag with out all of the extras.

    Now running HP Pavilion a6528p, with Win7 64 Bit OS.

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    Re: USB Hub

    Ooh that is rather nice and as it stipulates."...elegant..." my 233Gb HD produces a lot of heat and I have to place it in its stand because the aluminium casing really heats up enough to hurt, but it keeps my coffee warm <img src=/S/grin.gif border=0 alt=grin width=15 height=15>
    Jerry

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    Re: USB Hub

    Stuart

    Would there be any way of reassigning the amount of power suppliable to a USB device? Such as could cope with Jerry's 1A disk?

    John
    <font face="Script MT Bold"><font color=blue><big><big>John</big></big></font color=blue></font face=script>

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    Re: USB Hub

    No way that I know of, I think that each device tells the hub the maximum power that it might draw, and the hub reports that figure.

    According to Wikipedia "Equipment requiring more than 500 mA, hubs with more than 4 ports and hubs with downstream devices using more than four 100 mA units total must provide their own power."

    StuartR

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    Re: USB Hub

    That's an interesting article, Stuart - thanks!

    John
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    Re: USB Hub

    Some bus-powered drives come with an second "power only" USB cable (also, I've seen a PS/2 cable). Not sure whether your drive has this feature.

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