New-York tribune., 1918-03-31
Where Credit Is Due
By H. Clifford Brokaw

When the electric generator Of the
self-starter system fails to work it is
no light matter-also no light for the
car, usually. With the self-starter
lights, ignition and any number of add
ed devices depending upon the battery
it is no trif1e to have the generator get
out of whack, and the wiring usually
is such that when the generator is not
working it sets awry the whole cleo
trical system, SO that there are neither
ing motor, and the car is dead. There
fore, it is up to the owner to know how
to detect laxness in the generator and
know what to do when it does not de-
liver the goods
There are many peculiar things which
happen TO the generator or its appa
nages, so that one must needs know the
ms and outs of the entire electric sys-
TEN and the ways of detecting trouble
10 be able to put things in order and
keep the car moving.
If the generator will not deliver cur
rent, for instance, it might be due 20
the loss of residual magnetism. Ii. ne
generator there are one or more cleo
trio magnets; these magnets are COM
posed of soft iron with insulated wire
wound around them. When the cleo
trio current flows through the wires
the soft iron becomes strongly mag
netized. AS soon as the current stops
flowing the magnet loses its power,
but the iron always retains a small
amount of magnetism for time. This
Is called residual magnetism.
When the engine is started and the
armature IN the generator revolveS this
small amount of magnetism is what
starts the generation OF current Under
certain conditions, if the generator is
lett standing for long time, this re-
sldual magnetism will be lost entirely
and the generator will not deliver cur
rent when the armature is revolvetls IN
order to start it, all that is necessary
IS to send current from the battery.
through the generator; the residual~
magnetism will be restored and the
generator will work. This is done by
closing the cut-out by hand for minute
or less
Other cases of failure OF the gem
orator to deliver current are loose wire
connections in the generator. short cir
cult of the coils of wire wound on the
armature or field magnets, short cir
cults due to broken or misplaced brush
springs. or connections of the generator
becoming loose or misplaced.
Sometimes the brushes will become
worn so short that they will not reach
to the commutator. Sometimes they
will stick in the slides SO that the
springs cannot push them against the
commutator. 1t also happens that the
commutator becomes so dirty. due to
accumulatlons of grease, that the
brushes do not make good contact
with it.
In the regulator, which governs the
output of the generator automatically,
the contact points may become dirty
or the springs become weak or broken,
so that the current cannot pass.
Sometimes the coupling which con-
meets the armature to the shaft will
slip or break, SO that the armature will
not rotate. Many generators are pro-
vlded with fuse to protect the wind
lngs in case the battery lead is dis
connected, or the generator is over
loaded; where such fuse exists this
Is naturally the first place to look for
trouble. Any loose wires between the
generator and regulator or anywhere
IN the generator circuit might cause
failure to generate current
Noises in the generator NAV be
cansed by the armature striking the
neld pieces, due 20 9ens snart or badly
worn bearings, or by the bearings
themselves if they are badly worn or
not properly fabricated. Worn gears
Or coupling, or gear or coupling loose
on shaft, will give decided knock or
rattle. Some armatures are driven by
an overrunning clutch, and while it is
net usual for them to give trouble,
failure of the armaturc to rotate might
be traced to that source.
An unusual sound that was hard to
locate for long time was overcome bv
adjusting the cut-out. This was a sort
OF whine or whistle in the generator
at low engine speeds, and was due en-
treiy TO magnetic action within the
generator. 1t was found that when the
cut-out closed and put the load O,
the generator the noise disappeared. :.
SO TO overcome the noise when the en-
k'"e was idilng the cut-out was ad-