12.22 Ignition systems – Solid State

12.22.2 Describe the principal features and components of a typical solid-state ignition system.

A solid-state ignition system replaces mechanical components with electronic circuitry to provide more accurate and reliable ignition.

Principal Components

• Power source
  Supplies electrical energy (battery or alternator-driven system)
• Electronic control unit (ECU) / ignition module
  Controls ignition timing and spark generation electronically, eliminating mechanical contact breaker points
• Triggering device
  Uses sensors (e.g. magnetic pickup or Hall effect sensor) to detect engine position and signal when a spark is required
• Ignition coil
  Steps up low voltage to high voltage required to fire the spark plugs
• Capacitor (in some systems)
  Stores and releases energy to assist in producing a strong spark
• Distributor (or electronic distribution system)
  Directs the high voltage to the correct spark plug at the correct time (or uses direct electronic distribution in more advanced systems)
• Spark plugs
  Ignite the fuel–air mixture in each cylinder
• Wiring and connectors
  Connect and transmit electrical signals between components