Thank you for such a nice comment. To learn and understand each circuit diagram. First of all, if you want to understand a circuit diagram, you need to understand the symbols of the parts used here. Resistance, diode, capacitor, relay, and IC, each of them has a symbol inside the diagram. Resistance does not have a plus or minus. Capacitors have a plus or minus. And some capacitors do not have a plus or minus, you have to understand it through the symbol, it is mentioned there. You have to understand how a relay works by looking at the symbol. A diode has a symbol that current flows in one direction and blocks it from the opposite direction. And each circuit diagram is real. When you take a small circuit in your hand, you will not understand anything about it. When you see its diagrams, it will seem easy to you. The theory of each circuit diagram is to understand where the lines have gone in the circuit and which parts are connected to them. If you want, I can show you a diagram of a circuit I have in my hand and how it works. If I have time, I will create a diagram of a device I use and show it to you through your comments.