Vin pin + power jack

Hi everyone,

I know that the power jack have a 5v regulator.
i’m connecting the board to 9v\500mA dc adapter by this power jack .
i understand that when i’m using the power jack, the Vin pin turns to OUTPUT.
my question is how much voltage\current is now in the Vin pin??

*added a picture



Basically look at the schematic.
There is a seriese diode rated at 1A, so the output voltage will be 0.7V less than the voltage you put in to the jack and the current limit should be just under 1A.