The first step in electronics is understanding the concepts of current and voltage. There is a hydraulic analogy that helps to understand electricity, but here we will try to cover how it works on atomic and electron level.
Power Supply Unit (PSU) for the 3D printer is usually a large block that floats around the desk and is not connected to the printer. It is usually forgotten to integrate into the design. If you are lucky you can find mods on thingiverse, but I had no luck and had to design one myself.
If you are impatient and don't want to wait too long for your print to finish you can look for a solution in the E3D Volcano hotend. It is able to extrude filament a much greater speeds than a normal (V6) extruder. But it comes at a price of sacrificing the print quality.
The basic building blocks of FPGA chips are logic elements (LEs). A logic element consists of LUTs (look-up tables), which are basically programmable logic gates. This gate is a multiplexer and can be build out of NAND gates. This small project is a breadboard implementation of this concept.