Lydecker:
Hi,No I do not think it acts like a SPDT switch! Like I said, I am happy with the 'descriptive' purpose and operation of the MOSFET - i.e it is switching USB 5V either on or off. What I am not happy with is the way the terminals of the MOSFTET are drawn in the schematic.
Please see my attached image.
Circuit A is what has been drawn on the schematic.
I believe that what should have been drawn is Circuit B.
Any comments?
Thanks
Yes, don't guess or postulate. Get the datasheet for the specific FET and see it's terminal pin out and then look on your board to see if it's wired as drawn or not. The fact that it works as presently installed on arduino boards is not in question, just how the FET might be being used. Mosfets are able to conduct current in either direction to and from drain and source, that is also known.
Lefty