I am working on constructing a box which has three USB ports which will only be used to power USB devices and not use any data features. The key to this project is to have the power to each female USB port be determined by potentiometer setting. I think I have a pretty good idea of how to do this (relays), but I have a question about power consumption:
See I would like it so this box would only have one power plug on it which would power the Arduino and also the USB ports. What would you think an appropriate power supply would look like? Clearly it must be 5Volts but how much current would I need? If I got a 5volt 2.5A supply would it be sufficient? I am not sure how much current the devices connected to the usb port would draw? Also if you could give some guidance on wiring this together, could I just connect the power supply to everything in parallel?
Thanks, and I will update this page with info on my project and code to help anyone else trying something similar, currently designing a schematic with fritzing software (very nice http://fritzing.org/ ).