Trade of Motor Mechanic - eCollege
Trade of Motor Mechanic - eCollege
Trade of Motor Mechanic - eCollege
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Module 4 - Unit 1 Basic Ignition Systems<br />
<strong>Trade</strong> <strong>of</strong> <strong>Motor</strong> <strong>Mechanic</strong> - Phase 2 Course Notes<br />
3.2 The Battery<br />
The battery provides a source <strong>of</strong> energy to supply current to the<br />
ignition primary circuit for initial starting purposes. It forms part<br />
<strong>of</strong> the ignition primary circuit and acts in conjunction with the<br />
alternator to supply current to the ignition system throughout engine<br />
operation.<br />
3.3 Ignition Coil<br />
The ignition coil is a step-up transformer, which raises the nominal<br />
battery voltage <strong>of</strong> 12 volts up to the many thousands <strong>of</strong> volts<br />
necessary to provide a spark across the spark plug electrodes. A<br />
standard ignition coil has a rod-shaped laminated iron core, which<br />
is located centrally by an insulator at its base.<br />
The secondary winding with 15,000 to 0,000 turns <strong>of</strong> very thin<br />
enamelled copper wire is wound around the core and is insulated<br />
from the core by layers <strong>of</strong> treated insulated paper. The primary<br />
winding, with a few hundred turns <strong>of</strong> much heavier copper wire, is<br />
wound on the outside <strong>of</strong> the secondary.<br />
9<br />
Revision 2.0 July 2007
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