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LESSON 05 · Foundations

Reading Circuit Diagrams

A circuit diagram is just a map — learn the map legend once.

A schematic replaces real components with standardized symbols, connected by lines representing wires. It doesn't show physical layout — a diagram and the actual breadboard it describes can look nothing alike.

  • A straight line is a wire.
  • A dot where two lines cross means they're connected; no dot means they just pass over each other.
  • Every symbol has a reference label (R1, C2, D3...) and often a value (220Ω, 100µF).
WIRE JUNCTIONA filled dot marks a real connection between crossing lines; an unmarked crossing is just two wires passing by.

You'll see the individual symbols for each component as you meet them in the lessons ahead.