Quick question - 3x5m usb leads + hub - will the hub need to be powered?

As the title says really. I have 3 x 5m usb extension leads, the kind with the repeater box on them. (3 of these: http://www.scan.co.uk/Products/5m-Ne...ter-NLUSB2-EXT)

I presume the active repeater thingy takes power from the 5v USB supply, but had assumed it would be fairly minimal (windows seems to see each lead as a generic usb hub). I have an old USB hub that can be powered, but I seem to have lost the power supply for it. I understood though that you could usually run them un-powered if you were only using low power things plugged in.

I'm only plugging in a mouse and a remote control - I'm using the tv in the kitchen as a second monitor for pc in the study so I can watch stuff in the kitchen. I wouldn't have thought either the mouse or remote were power monsters, and when plugging the hub directly into the pc all works ok.

But when using the long usb lead with the 3 repeaters, the hub lights come on, and windows does the usual duh-dah, but Windows doesn't recognise either the mouse or the remote. Either the remote or the mouse work ok if plugged directly into the long usb lead with the 3 repeaters.

So I figure either I'm right at the power limit, and whilst it can cope with 3 repeaters and mouse or remote, it can't cope with the extra power the hub needs. Either that or the hub isn't quite right.

The other option I guess is that cutting one of the 5m wires in half, then splicing all the wires together (so I could get in down behind plasterboard) has knackered the wire. But as above, the 3x5m extension including the lead that has been butchered works fine if the mouse or remote is plugged directly in without the hub.

A hub doesn't need that much power does it?

Any thoughts welcome before I go out and grab a powered usb hub. (and try other things like turning everything off and on again :mrgreen:)

You could try combine a 5m repeater cable then a standard USB extension cable. Data doesn't need to be repeated except at the mid point of the cable. Power hub is the first thing I would try.

At work I ran a 5M USB cable (not a special type) into an unpowered hub, and that was fine. When I got up to 4 devices (wireless mouse + KB, wired KB, wired mouse, USB stick) I needed to power it. For the first three it was fine, but the fourth pushed it over.

It wouldn't surprise me if everything is fairly weak by the time it reaches the hub and the power might just make the difference... hard to say though.

Should be OK.

The mouse at the far end will draw 100 mA, each repeater will take 100 mA for itself, and the PC at the host end will supply 500 mA.

There is a menu under the device manager in windows that will let you know how much juice each USB device you have connected, including any hubs are drawing.

Cheers for the replies :thumbsup:

I will have a play tomorrow - as chrestomanci says, each of the repeaters states 100mA - though presumably that's a standard figure rather than actually being measured (they're in serial for a start...). I'll stick the actual hub in to see what that comes up with, but guessing it'll be 100mA

So 3 of them and then the actual hub on top. + 1 mouse and the remote?? Probably pushing it aren't I :mrgreen:

Powered hub here I come.

Again - thanks!