k-pi wrote: ↑
Sun Nov 18, 2018 4:51 pm
I was presuming 600mA per USB motherboard hub/port. If that is wrong, then there must be something else coming into the equation.
The 600mA was in the Pi2B, with an option to set it to 1200mA. Later--and certainly the Pi3B/Pi3B+--defaults to the higher power rating. The Pi0/Pi0W don't have the power protection circuits at all, not even the polyfuse, so those boards will only be limited by the PSU and the current carrying capability of the PCB traces and the feed cable.
Since the A, A+, and Pi3A+ (presumably...I don't have one yet) have power protection circuits, the current available to the (one) USB port should be whatever the rest of the board doesn't need up to the limit imposed by power regulation, PSU and cabling. That *should* be in excess of the 1.2A from a Pi3B/Pi3B+ (assuming a sufficient PSU and power cable).
I have used Pi0, Pi0W, and A+ boards with the passive Monoprice hub I previously linked to. I recently did minimal testing of a Pi0W with a D-Link
DUB-H4 hub and found no issues. I will do further testing with the D-Link when I get a Pi3A+ (probably some time this coming week...it is in transit).