Apologies if this seems to be a repeat of a question that others have asked many times. I have tried searching the forum, but the answers don't seem to fit my needs...so here goes:-
I have connected a 5vdc 2A phone charger power supply to the Vin and Gnd terminals of a Nano, and taken a tapping off to power a 4 relay driver board. Each relay draws about 10mA when energised.
I want to use the 5v output from the Nano to drive a voltage divider (with a current load of about 500uA), but find that, even with no relays being energised, the '5v' Arduino pin is only at about 4.2vdc. I can only assume that the on-board voltage regulator has robbed me of the missing 0.8v.
Would it be sensible therefore, to replace the 5v PSU with, say, a 7 to 9vdc PSU, and would this stabilise the Arduino's 5v pin to its nominal value of 5vdc?
A second apology may be due too, as I haven't managed to grasp the technique to show my circuit graphically yet, and it seems that you helpful folks love a schematic or two.