The question seems simple, but there's more to it:
I'm connecting 4 74HC595 shift-registers to an arduino pro micro. 28 of the 32 outputs will be used to control LED segments of numbers. Each segment uses 14-20 LEDs and so I will be using a transistor for each segment. Now here's my problem: With the maximum amount of LEDs activated (at time 08:08), the LEDs will draw nearly 10A. How can I use another transistor to make the shift-registors work with the arduino even though it shouldn't be drawing all current from the arduino, but from an external power source. I have found a suitable adapter from 230V to 5V 12A. The 12A is just to ensure that nothing goes wrong. The LEDs alone will draw 9.76A.
I know how to connect the arduino to the power source, but how do I run extra wires from the power source around the arduino to provide the LEDs their power?