Fairhaven herald. [volume] (Fairhaven, Wash.) 1890-????, 1892-04-03
WHAT A DYNAMO IS.
Description of the Main Principle of an
Electrical Machine.


Electrical Machine.
The collection Of electricity or its gener
alton, as it is often called, is no more or
less mysterious than the generation of
heat For those who make no pretensions
to understand the governing principles I'M
DERIVING the generation Of electricity by a
dynamo we present the following brief ex-
PLANTATION, which we hope may be easily
grasped:
Perhaps every reader has played with
common horseshoe magnet. No one can
have one on his hand, even for few mo-
ments, without noticing that the small
piece at the two ends called the armature,
when brought close TO these ends, not be-
ing allowed to touch them, is affected by
some invisible influence which tends 10
draw it toward these ends. This mysteri-
Gus influence is called magnetism. On
laying a horseshoe magnet on piece OF
paper placed in a horizontal plane and
loosely sprinkling iron filings around these
ends it can be seen that there is an appar-
emit current of this influence projecting
into space from the ends and running
across the space at the open ends OF the
magnet. These imaginary projections or
currents Of this mysterious influence are
called "lines of magnetic force"
Here we have the magnetic force, and
the next thing is to get the electricity. BY
moving an armature across these lines OF
magnetic force at the ends OF a magnet
we find it requires an expenditure OF
energy. In the case of dynamo we obtain
this energy from steam, water power or
some other source The generation Of
electricity is as easily understood as the
method Of getting power by steam en-
| CINE. 1t is known that if we take con
ductor Of electricity, like a common cop
per wire, and by any means cause it TO
move through lines Of magnetic force in
a certain direction, that electricity will be
developed in this conductor No one pre-
tends TO explain why. This is the whole
/ mystery of the dynamo, with all its as
| tonishing possibilities in the service OF
man.
| We know how to do it, but are as much
/ in mystery about the reason nature acts
/ in this way as we are to explain why an
/ apple goes down instead Of up when rolled
/ from yoH open hand.
A dynamo consists principally of two
| parts, one of which is a large mass Of soft
cast or wrought iron called the magnet
and the other part is called the armature
Soft iron does not remain permanently as
d
| However, some magnetism always remains
stored up in the iron. There is germ Of
magnetism great enough to be easily anC
quickly increased when properly handled
by well known methods The revolving
shaft, as seen in the ordinary dynamo, il
called the armature. The armature il
usually constructed by having hundred
of insulated copper wires in it and is mad
to revolve at a high velocity by some me
chanical force, such as steam. Suppos
this speed is 900 revolutions per minute
which is not unusual, and that we hav
500 wires on this armature, then we vii
have, as the armature revOlves, wha
would be equivalent TO a single wire cut
ting across all the lines Of magnetic fore
10000 times each minute.
The magnet generally surrounds tn
armature, and these magnetic lines o
force are shooting through the armatur
in a continuous stream at an inconceivabl
velocity All the wire conductors on tn
revolving armature, as they move through
these lines Of magnetic force, are constant
ly picking up their little share of electric
ity and unloading it by means of ingen
ious mechanical devices connecting witt
the conducting wire that leads from tn
dynamo, and receiving the returning cleo
tricity on another wire leading back int
the dynamo.
One of natures wonderfully mysteriou
laws causes soft iron to become magnet
when surrounded by current Of eleC
tricity. In the ordinary dynamo this lay
is Of the greatest utility. As the electrica
current is being collected by the revolvin
armature it is led around the magnet, an
thus the magnetic germ is quickly change
into a mighty force, again feeding th
armature which transforms it from mag
netic to electrical force.-Mechanical an
Electrical Progress.