USB Mini Light & Fan not working when connected to Phone :
Mini USB Fan or light like the one shown below uses the power from Micro USB port of the phone to work.
However the power on the USB port is present only in phones which support USB OTG function.
Hence these types of devices may not work in all phones.
Before purchasing such device for the phone, user is advised to check if the phone supports the OTG function.
If OTG function is not supported by the phone, then it is not going to work.