Lesson3/Learning Event 1
FIGURE 22. IGNITION COIL CONSTRUCTION.
Now let's study the construction of the coil. The illustration shows a coil that has been cut away to
show the primary winding, secondary winding, soft iron core, and the terminals for the windings.
The primary winding is the large wire, and the secondary winding is the small wire. The actual
diameter of the wire used in the secondary winding of the coil is about the same as one of the
hairs on your head, or less than 0.005 of an inch. With such a small wire, we can have thousands
of turns of wire in the secondary winding in a small space.
One end of the secondary winding is connected to the high-tension lead of the secondary terminal
on top of the coil, while the other end is usually connected to one end of the primary winding,
although it may be grounded to the metal can that surrounds the coils and the core.