Understanding symbols, nets, and connections before you start designing

Introduction

So you want to design a PCB. Or maybe you just need to understand an existing circuit.

Either way, you need to read a schematic .

A schematic is the blueprint of your circuit. It shows every component, every connection, and how everything fits together — without worrying about physical placement or board shape.

If you’ve never seen one before, it can look like a mess of random symbols and lines.

This guide will teach you how to read one.

The Basics: What Every Schematic Shows

Every schematic has three fundamental things:

- Components (symbols representing resistors, chips, connectors, etc.)

- Nets (lines representing electrical connections)

- Reference designators (labels like R1, C2, U3)

Once you can identify these three things, you can understand any schematic.

Reading Component Symbols

Different components have different symbols.…