Hi, when you connected the bench supply, did you connect the gnd /neg of the arduino circuit to the gnd/neg of the bench supply.Tom....
As I said I have no electrical background and I was always under the impression that "ground = ground" (so it doesnt matter which one you take). Obviously that is not the case - just why?
However could you elaborate a bit as to why this is is?
QuoteHowever could you elaborate a bit as to why this is is?You might want to read this it has a good diagram explaining things:-http://www.thebox.myzen.co.uk/Tutorial/Power_Supplies.html
but why doesnt the current use the path that is there to go to the "other" ground provided by the bench supply
dissonance when you see a power system