Ok,so the jally is going to use 4.5 watts,this is what I found out about USB 2.0,tell me if I'm correct:
Besides a data link, USB provides 5 +/- 0.25 volts to power an otherwise unpowered device or charge a battery in a self powered device.
A USB controller or hub is required to power one unit load (100 mA, a low power load). It can optionally power up to 5 unit loads (500 mA, a high power load).
The spec is silent about intermediate loads, so I assume that the sources deal with just the two cases.
Either a load is low power (like a keyboard or a mouse) or high power (like an iPod or PDA).
500 milliamps = one half amp (1000 ma per amp).
So, .5 amps x 5 volts=2.5 watts.We'll definitely be needing those dual USB cables won't we
I know there's a thread about this somewhere,but couldn't find it,sorry
What USB hubs are good enough for this application (running multiple Jallies),I've never had a need for these,so I'm unsure of what powered hub requirements are needed.