Montpelier examiner. [volume] (Montpelier, Idaho) 1895-1937, 1912-02-09
THE GENERATION AND APPlI-
CATION OF ELECTRIC POWER
BY ARTHUR IoBsox

Electrical energy may be generat-
ed in a number of ways. The most
important commercial method is by
electromagnetic induction. 1t is as
suned that the reader is familiar
with the common 'horseshoe" mag
| net; a piece of magnetised iron which
has the characteristics OF attracting
with some force various kinds of
| metals A common method of mag
| netising a piece of iron (say one inch
in diameter and six or eight inches
long) is to wrap a number of turns of
insulated wire uniformity around the
\ iron in such n manner that the iron
| will be withina coil of wire. Assume
| that the ends of the piece ofIiron are
allowed to project outward from the
coil of wire about one-half inch If
| the terminals of the wire are now
! connected to some source of direct
! electric current the iron will become
magnetised. The intensity of the
magnetism will depend upon the
strength of the electric current. One
end of this piece of magnetised iron
/ will have what is called .snortlin
pole, and the other .ssouth' pole.
| depending upon which direction the
electric current is flowing in the coil
of wire. If the current is turned off
most of the magnetism in o.so iron
will disappear, only to reappear
| when the current is turned on again.
The action of the electric current is
not only to magnetise the iron but it
has also created a magnetic field
around the iron, composed of Lines
of force :" These lines of force are
assumed to move outward from the
north pole of the piece OF iron ana
cutter again at the opposite end, or
south pole. The strength of the mag
netic field surrounding the iron will
remain constant so long as tie
strength of the electric current re-
mains constant.
1t has been found by experiment
that if piece of wire is moved
t rough a magnetic field, such as has
been described, in such a manner AZ
to cut the lines of force in the mag
netic field an electric current will be
generated in the wire This method
of generating electric current is
known as electromagnetic induction
To get the best results the wire should
: he moved across the magnetic field al
: near one end of the piece of magnet
ised iron as possible, without actual.
. ly touching it. and at right angles Il
the length of the iron.
= In the common generator the abov,
principle of generating electricity i
a applied. In stationary field gener
e ator the poles consisting of pieces o
t iron within coils of insulated wire
r are arranged in the circumference o
:. circle. The revolving part, o
! armature as it is called. is circular Ii
r form and rotates within the outer ar
t rangement of poles. These poles ar
!. magnetised by passing a direct elec
= trio current through the coils of wir
d surrounding them. There are alway
a two or more poles in single general
q or, and they always exist in pairs
q that is, for every south pole there
an opposite north pole. Around th
V outer circumference of the armatur
Is or rotating part, there is arranged
VI va DfhtdItti Y
the shaft upon whice the arrnatiIre
i mounted. These insulated wires al
ir placed in slots or small grooves, an
a. as the armature rotates these wire
- are carried through the magneti
fields, or lines of force, issuing froi
: the poles, thus causing an electr
Ncurrent to be generated. The quaint
k ~ of electricity or the strength of tf
r electric current which can be genei
II ated I'm this manner depends upon tt
>. Intensity of the magnetisation in ii
pole pieces and the speed with while