I am programmer that just started learning electronics and Arduino. I built this simple circuit on Autodesk Circuits earlier. Originally I used 220 ohm resistors. Then when I ran the simulation and turned on more than 4 of the leds the simulator warned that I exceeded the max current for the shift register.
I then upgraded to 560 ohm resistors which solved the problem.
What I would like to know is how can I calculate the current through the shift register for each n-number of leds I turn on? That way I can calculate the right resistor that I need before I burn out my electronics.
Thanks for the help on this.