Electronics for power supplies
First, I apologize for being (almost) the hardware version of a "script-kiddie". I do want to learn the techniques involved but all of the electronics courses I've found work the wrong way around. They teach "this is what we have and this is what you can do with it" whereas my brain works in the "This is the problem, here is a solution and this is why it works." manner.
This is how I learned software but when you get it wrong you can start again without losing the magic smoke!
I have a 250ah, 12V battery bank, multiple DC devices requiring power and, eventually, several power sources for recharging. I also have several MC34063 chips and a few higher amp chips (somewhat optimistically as it turns out).
Firstly, is there a practical course online that is built around this?
Secondly (and probably extremely basic), if a device draws, for example, 3A is it self-limiting or do I need to put something between the source and the device too restrict the power?