Hi,
Not possible, you need separate power supply for your device interface. USB port can supply only 5V at 500mA for all ports connected to a hub.
Regards,
Laktronics
actually this is nt possible at all.
you must use external source for required current.
current amplifier should nt use bacoz it may hamper ur port. becoz 2 amp is quite a large amount current in dc circuit;infact u might nt able to do this.
use relay with xternal supply or u can use the power supply of ur pc.