MEPX
Chapter 9 of 10All chapters
  1. 1Charge and current
  2. 2Voltage
  3. 3Resistance and Ohm law
  4. 4Series and parallel
  5. 5Power and energy
  6. 6Components
  7. 7AC and DC
  8. 8Electrical safety
  9. 9Reading a circuit diagram
  10. 10Everyday electricity

Chapter 9 of 10

Reading a circuit diagram

Symbols and tracing paths.

The conventions

Symbols are standardised, lines are wires, and junctions with a dot are connected. Reading a diagram means tracing the path a current can take from source back to source.

  • Every current needs a complete loop, or nothing flows.
  • Ground is a common reference point, not necessarily the earth.

Measuring

A voltmeter goes across a component and a ammeter goes in line with it. Connecting an ammeter across a supply is a short circuit and a fast lesson.