power from USB port.

[vutonium]

Hey guys I've many a times seen people selling USB fans or USB keyboard lights.How do those work?Can we draw power from the USB port???
Can anyone provide me with the voltage and max current ratings of a typical usb2.0 port???? i tred google but the results are too complicated. i didnt get most of it . can anyone please simplify???

 

[Sukhdeep Singh]

Yes USB has power. Read more about power here
*en.wikipedia.org/wiki/USB#Power

 

[Choto Cheeta]

hope u have a good psu and a strong mobo