|
USB already draws power, well in 1 of the two modes:
4 wire:
0V Data- Data+ 5V
You could draw 5V down to the "hub" and then share it out between devices, however that would probably not work that well (USB ports do not have high currents really so a massed expander would probably need to be powered).
This idea already exists though, an MP3 player or suchlike could have two USB plugs on it, one that brings power down to it and one that powers a sub device (or many devices especially if they are unpowered!)
A better idea of what you are planning would allow better advise, but there are many books on USB design and google is always your friend.
|