BTW how much current does Arduino Draw from its outputs? Is it 40mA?
The resistance (R) of the external components determine how much current is sunk or sourced from an Arduion I/O pin, as in Ohm's Law, I=E/R.
The Arduino has a safe maximum I/O output current rating of 40ma, but again the external circuit determines what the actual current flow value will be.
Lefty