I've got two of those Targus USB LED lights...specs on the docs say:
Operation - 2.5 to 5 volts, below 2ma
Sleeping - 2.5 to 5 volts, below .50ua
but those are what the USB LED needs/uses...
--------------------
The following info is from
Dan's Data:
As you look into a rectangular Type A USB plug, aligned in the usual logo-on-the-top way, the rightmost contact inside is number 1 and the leftmost pin is number 4.
Pin 1's the five volt contact, pin 4's ground. The two pins in the middle are the data ones, which you don't care about for mere power supply purposes.
The
USB spec only allows for 500 milliamps (mA) of current from each powered port. Root hub ports on your computer are powered ports, and so are ports on a "self powered" hub. That includes standalone hubs with their own plugpack power supply, and ought to include ports built into things like monitors as well.
"Bus powered" USB hubs that don't have their own separate power supply can only supply a total of 500mA from all of their ports put together.
--------------------
However, don't take anything that I say as fact...I only did a Google search for "USB Port Power Spec"...better verify this data with someone or somewhere else. Someone here must know???