I need some assistance in designing a proper powering solution for my project. The project is an Arduino-like board, with a lot of WS2812B's.
My power requirements are about 4A of current at 5V, where 500mA is for the electronics (processor and other misc. equipment), and 3.5A for the LEDs. The problem is, that the 500mA needs to be "high quality", i.e. regulated power. For the rest, I only need 5V-ish unregulated power.
I have considered the following:
1. Power everything from a decent plug-pack that can supply at least 4A@5V of regulated power. But these are expensive, and I only need 500mA of that. So, I figured there must be a better solution.
2. Power everything from an unregulated 9V or 12V plug-pack, and then go through a step down converter that can supply 4A@5V. But again, these are expensive, and I only need to regulate 500mA. And I get a lot of power loss when I convert mains twice, once to 9V and then to 5V.
3. Power everything from an unregulated 5V plug-pack (more affordable), and then "regulate" only a 500mA. But to have regulated 5V from an unregulated 5V, I need to step up the voltage well above 5V, and then step it down to my requirements. I find this idea "overcomplicated" (lots of extra parts), I assume there must be a better engineering solution to that problem (I've heard about SEPIC converters, but those are well above my skills at this point
).
4. Design two separate power circuits -- one for the electronics and one for the LEDs, and power them with two separate plug-packs. I would like to avoid having two cords and two power supplies.
What is the best option for me?