The morning Astorian. [volume] (Astoria, Oregon) 1899-1930, 1908-03-20

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chine, yet il is all simple enough
when carefully explained Of course
III the latest types ot thrcc-phase
motors such an explanation would be
complicated but the working princip,
les remain the same as in the simp.
lest form OF motor BY way OF ex.
planation take the direct current bi.
polar motor, which rs its name imp.
lies, consists el single field maSnet
Of two poles The magnetizing coils
Of this field magnet are placed in .
solid frame with the polar ends fac.
ing leaving a suitable space between,
kaown as the magnetic field, in which
the armature reyokes When an
electric current Is passed through the
magnetlzing coils OF the field magnet
q powerful magnet is produced OF
which one end is the north, or post.
i've pole and the other and opposite
end the south, or negative pole The
lines OF invisible magnetic force ex-
tends across the Intervening space,
Now il loop Of wire, through which
was flowing an electric ctrrept was
passed downward straight between
these two poles, cutting the lines OF
magnetic force at right angles, Il
mysterious power would force the
wire back to the top OF the magnetic
lines, Therefore the armature which
rotates between the poles OF the field
magnet in a motor is nothing more
than series Of coils Of wire through
which an electric current is passing,
Those coils which are at the bottom
OF the lines OF magnetic force be-
tween the poles OF the field magnet
are being forced upward on the posi-.
tive side and downward on the mega
tive side. This motion would stop rs
soon as the armature coils adjusted
themselves in accordance with the
lines OF magnetic force il it wasn't
for little device called a commutator
The duty OF the commutator, which
Ii divided ring OF insulated copper
fastened 10 the axle OF the armature,
is periodically to reverse the current
passing through the armature coils
SO they never adjust themselves to
the magnetic force flowing between
the poles OF the field magnet. No
matter how fast or slow the motor
runs, as the armature revolves. the
brushes" which feed the current TO
the armature coils by contract with
the split surface OF the revolving
commutator, reverse the current in
time to keep the strange magnetic
force always exerting its invisible
powers to drag one side OF the arma-
ture up and to force the other side
down. This force gives the arma.
ture continuous motion and power
Increasing the electric current in the
coils increases the power OF
this magnetic pull and the horse
power Of the motor grows accord
ingly.
A glance at the motor running so
quietly and doing so much work for
so small body will reveal all these
facts. The field magnets can be
readily seen and II takes but little
imagination to realize the lines OF
force extending between the
opposed poles In the surface OF the
when the motor Is stopped,
the coils can be seen imbedded ~
slots. These coils are made OF in
suIated wire in the smaller motors
and heavy, insulated copper strips in
the larger machines. After these
things are noted it Is easy TO under
stand the powerful magnetic force
which Is pulling continually to adjust
the coils in the armature TO a certain
position and then just as the task
seems to be completed, the little re
yolying commutator has reversed the
current and the work has to be done
ali over again, And so on minute
after minute. day after day, year after
year the magnets are working TO set
the lines Of force right accordingly to
natures own irrevocable laws and
man keeps them ever opposed and
utilizcs the energy expended to turn
the wheels Of his industries, drive his
railroad trains and to supply him with
power for everything.
phNIET AppI .ETON DEAD,