Angelo9999:
The 5V pin is connected to the USB 5V through two MBRM130LT1G Schottky diodes. The maximum current you can draw from the 5V pin depends from the power supply, and these diodes can work up to 1 A.In your case current limit will be 500 mA due to USB limits but a part of that current is used to power the Yun so the current you can actually draw from the pin is lower.
Yes, that's the answer I'm looking for!
So even if I put it on a USB charger that can saupply 2A, I'm still limited by the 1 A of the diodes? I've read that the Yun can pulls up to 400 mA, so that should be plenty... a 600 mA buffer. I don't need to power a lot, just a few sensors.