Briggs & Stratton 86262GS, Familiarization & Troubleshooting Manual

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If the coil is wound around a core of magnetic material, such
as iron, the strength of the magnetic field at the north and
south poles is greatly increased (Figure 1.12).
This happens because air is a poor conductor of magnetic
lines and iron is a very good conductor. Using iron in a
magnetic path may increase the magnetic strength of a coil
by 2500 times over that of air.
The strength of the magnetic poles in a coil of wire is
directly proportional to:
The number of turns of wire.
The current (in amperes) flowing through the wire.
A coil carring a current of one ampere through 1000 turns
of wire and another coil carring 10 amperes through 100
coils of wire will each create a magnetic field strength 1000
ampere-turns (Figure 1.13).
The term “ampere-turns” is the measure of the strength
of a magnetic field.
Direct Current (DC)
The current flow created by a storage battery flows through
a conductor in one direction only.This type of current flow
is called
direct current or (DC) .
Alternating Current (AC)
Alternating current or (AC) is the flow of electrons
through a conductor first in one direction and then in the
other.This can be explained by showing the operation of a
simple alternating current (AC) generator (Figure 1.14).
8
Section 1 • Generator Fundamentals
Portable Generator Familiarization & Troubleshooting Guide
Figure 1.12 — Iron Core Increases Strength of Field
Figure 1.13 — Example of “Ampere-Turns”
Figure 1.14 — An Aternating Current Generator