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12.20 Ignition Systems – Magneto Ignition
12.20.2 Describe the principal features of a typical magneto ignition system (dual, independent, engine-driven magneto systems with two spark plugs per cylinder).
A typical magneto ignition system consists of two independent, engine-driven magnetos, each of which is connected to two spark plugs per cylinder.
Each magneto contains a permanent magnet, a primary coil, and a secondary coil.
When the engine is running, the magnet rotates past the primary coil, which creates a magnetic field.
This magnetic field causes a current to flow through the primary coil, which in turn creates a stronger magnetic field.
When the magnet rotates past the secondary coil, the magnetic field collapses, which causes a high voltage to be induced in the secondary coil.
This high voltage is used to create a spark at the spark plugs.
The two magnetos in a typical magneto ignition system are independent, which means that they operate separately from one another.
This design provides redundancy and ensures that the engine will continue to run even if one of the magnetos fails.
In addition to the magnetos, a typical magneto ignition system also includes a distributor, which is responsible for timing the spark to each cylinder.