Issues with powering my "LED-bar"

Using Arduino Project Guidance
#1

Hi guys,

I made this Led-bar for a project for school, now my problem is (badly not my only problem, but a big one for now) is that I can't figure out where to get my power from.

I really searched alot of forums and other sites, but I just can't figure it out (maybe I'm just blind or too noob to see...)

Here are some pictures of the project:

I figured out that, probably, it was a better idea to multiplex it, but since I didn't want to control the LED's solo, just by rows I did it this way. (it seems real messy aswell.. but hey, everyone has a first time)

I got three shift registers (595) to control them with.
Now, as my Arduino can't power all those LED's, I really can't figure where my extern powersource should be implemented in my circuit. (A guy in the store said to me I had to power it before the Shift Register, but could not tell anything more about it).

Is there anyone out there who can help me out bigtime, and let me become abit less of a newb in electronica?

Thank you so much!

#2

Use an old cell phone charger. Preferably one that can output 5 - 6 volts at 1 Amp.
You should also use NPN transistors (don’t forget the resistors), one per row and instead of controlling the rows directly from the shift registers, have the shift registers control the transistors and the transistors control their rows.

#3

Should be pretty straightforward - drive NPN transistors with the shift registers (or MOSFETs, but those look like wimpy enough LEDs that you don't need it) to control each row.

Power all the crap that's not on your arduino board with an external power supply - repurpose a wall-wart supply that puts out the appropriate voltage, and connect everything up to that, and connect the ground to the arduino ground.

If your arduino isn't going to be connected to some external power source, of course, you would want to power it from the same supply.

#4