This article applies for USB hubs: KUH-590, KHC-345, KUH-190, KNS-110B.
Some of our USB devices comes with a AC Power jack input that applies in case that the USB port on your PC can't give enough voltage to the USB device, a common error message would appear: "USB device not recognized". If this is your case, you can use a 5V AC adapter.
The Current for each device and polarity of the AC Adapter needs to be as follows:
KUH-190: 0.5AKNS-110B: 2A