OPERATING PRINCIPLE OF MAGNETO - IGNITION SYSTEM

Magneto is the special type of engine - driven alternate current (AC) generator. Magneto uses permanent magnet as the source of energy. By the use of a permanent magnet (basic magnetic field), coil of wire (concentrated length of conductor) and relative movement of the magnetic field, current is generated in the wire.

At first, the magneto generates electrical power by the engine rotating the permanent magnet and inducing a current to flow in the coil windings. As currents flows through the coil windings, it generates its own magnetic field that surrounds the coil windings.

At the correct time, this current flow is stopped and the magnetic field collapses across a second set of windings in the coil and a high-voltage is generated. This is the voltage used to arc across the spark plug gap. In both cases, the three basic things needed to generate electrical power are present to develop the high voltage that forces a spark to jump across the spark plug gap in each cylinder.

Magneto operation is timed to the engine so that a spark occurs only when the piston is on the proper stroke at a specified number of crankshaft degrees before the top dead center piston position.