External Adapter Power
The bq receiver is designed for an adapter input. This means in addition to being powered wirelessly there is an option to connected an alternate power source.
This could be USB power since it too is 5 volts.
The amount of power available from a USB port is dependent upon the its circumstance. You can have anything from 500mW to 2.5W available.
To ensure that I have 500mA of current available I use USB ports directly from a PC or from a powered Hub with sufficient power capacity.
This is well demonstrated with some USB powered external Hard Disks that require 5 Watts (5V @ 1A ) which have two USB connectors where one is a standard USB plug for communications and power and the other for just power.
Here is my test rig with external USB power lead attached (but currently turned off just for the photo).
I've tested by connecting it up to my notebook PC USB port and it works!
