Hello Everyone,
Lately I've noticed several products that get power from USB Y-adapter cables. At one end is 2 usb plugs and at the other is 1 plug. The two plugs at one end are placed into two usb ports. One of these two plugs do not have the data pins connected. The other end of the cable plugs into the device being powered. The thought is that if you have 2 USB 2.0 ports supplying 500mA each, this cable will allow you to pull 1A of current to power the device.
I intuitively kinda get this. My question is what happens when one port, for instance a USB 3.0 port, can supply 900mA and the other port being a USB 2.0 port can only supply 500mA. Will the result be additive in nature and you end up with 1.4A to use or will the over demand on the USB 2.0 port somehow limit the overall current to something lower. When the ports are unequal, I can't quite wrap my head around it yet.
Thanks for the help!
Skinny