usb hubs

[tony1941]

What is the difference between powered and non-powered hubs? I need to run my epson scanner and printer from the same port - which kind do I buy?? Thanks

[Ralph]

Generally, if the device you want to plug into your USB hub has its own plug in power supply or transformer, then an unpowered hub will suffice. If you need to plug in something that draws its power from the hub, such as an MP3 player that charges through USB or some scanners, then you'll need a powered hub.
If you've got the choice (or advance information), the best choice would be a hub that will work either powered or unpowered. I had a 4 port Belkin hub like this. Now though, I've got a 7 port Belkin hub that won't work with even a flash drive until you plug it in. :-(

[qapmoc]

Hi Tony, Ralphs answer is technically perfectly correct but it did not answer your question.
All USB hubs have power in them to drive attached devices, the difference is in where the power comes from. In a non-powered hub the power comes from the PC which the USB is plugged into, if you only have small devices connected like a pendrive this is adequate but anything big will take too much power from the PC and overload the power-supply and might cause you odd problems. A powered hub has a seperate power supply which plugs in to a wall socket and this can drive much larger equipments such as printers etc..

I hope this will help you out.