my usb dissconect for 1 sec from laptop duting a voltage fluctuation

[ikshit]

i live in india where there are 1 voltage fluctuation per minute. when my laptop is connected to ac and then a fluctuation occur my usb device disconnect , it works fine when my laptop is on battery power never disconnect when on battery mode, i used a ups for the solution but when a fluctuation occur the usb device disconnect , i also used a surge protector but no benefits.

why power fluctuation are affecting on usb? ,do usb device are powered directly from main when laptop is charging ? will it effect my laptop motherboard?

 

[westom]

why power fluctuation are affecting on usb? ,do usb device are powered directly from main when laptop is charging ?

If the laptop battery is good, then a laptop should automatically switch to battery so that nothing in the computer knows AC power was lost or restored. Your post implies your laptop has a defective internal power system that does not switch seamlessly to and from battery.