Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1919-06-29
S|MPL|F|ED LESSONS IN
CARE OF AUTOMOBILE
Automatic Cutout or Relay and Its
Functions Described by
Expert.
ACTS AS AN ENGINE SPEED
Voltage Regulators and Their Uses.
Gucrrlick Answers Numerous IN
quiricS From Car Owners, EN-
planning Their Problems.


starting and lighting when the en-
sne is idle. the generator will not be
'sendng current to the battery. but the
current from the battery will flow to
the generator. and so. unless some de-
vice. which Will disconncct The battery
and generator, Is used. the battery will
soon be discharged.
: The device used for this purpose Is
called an automatic cut-out and some
times a relay
Not only must The cut-out bc used
when the engine is idle, but also when
il is running slowly. as at the slow
speed the voltage of the current made
by the generator, Will be less than
the voltage 'orpressuro) OF the bat
terry. and under this condition the
current would also flow from the bat
terry to the generator. and so tire bat
terry become discharged.
From The above we see that tho
purpose of the Cut-o is TO disconuccI
The voltage OF the battery is greater
than the voltage OF the generator. aud
to connect them, the moment the gen
the battery
Acts ns An Engine Speed.
The cut-out is arranged to act a.,
an engine speed ot about $50 rcvo!u-
tons per minute or a car speed Of
YOU Will notice that the generator vii!
charge the battery only at car snceI
greater than hfteen miles per hour.
Let US see how the automatic cut
out operates. Were current of cleo
,ricity to Tow through coil r. Fig /.
In the direction OF the arrows. then
the core \ would become magnet
and would draw piece Of steel to it's
ENDS, II current We're also made 10
flow through coil ., in tho direction
OF the arrows, the magnetic strength
should the curren; flow through in
the reverse direction. then this coil
would act against the coil Il. and so
the core would lose its magnetism. or
IN other words, the magnetism created
by b would be absorbed By G. II is
on this principle that most cut-outs
Fig. . shows the condition Of
BoSch cut-out when The generator is
making current Of higher voltage
VIII notice. by studying the arrows
mat the current is flowing in the same
direction through both coils. Y and G.
me core is, therefore. a magnet and
mas drawn down tho button against
the spring action and so closed the
contacts. Thus the battery and gene
rator arc connected or cut in"
Fig. shows the condition when the
generator VOLTAGE is less than the bat
terry voliaG'. by studying the arrows
you VIII notice that the Currcn; flows
through the coils Il and G in opposite
directions. The maEnetizinE action OF
the one coil will now ncutralizc that
of the other, and so the core will
cease 10 be mcgnct and will no
longer draw down the button Tho
contact points viii therefore open. and
me battery and generator will be dis
connected on 'cut-out."
Position of Device Varies.
The position OF the cut-out varies
IN different makes OF cars. Sometimes
IL is placed on top or on the side OF
ne generator. and often it is placed on
the dash.
Should your battery become dis
charged overnight. It may he due TO
me contact points OF the cut-out stick
ing or 10 the spring. which pulls them
WHEN the engine is idle the contacts
should be open.
FAILURE Of the generator to charge
the battery may also be due to the
automatic cut-out. In this case tho
trouble will be due to tho contacts M
being pulled together, or TO the con-
as to make poor contact. Thev
should be closed al the higher engine
The Voltage Regulator.
Inc voltage OF the current made by
the generator varies with the spaoJ |
OF the armaturc, and at very HIN
engine speed II may be so high as IN
90 damage 10 the battery TO pre-
t rent t ms device must lie put into |
me! circuit which viii not permit the
voltage 10 get above a certain nrno,,nt
rms device is called a voltage reEu
Voltage regulators vary greatly E,
d fsF l &@ I ii5S c,a Tnsy mishi be
chanlciaf regnlaior. in which :. cover.
nor dlsconnccts the armaturc from liz
driving shaft when the speed b,.rnrnes
700 hish; t2J an electro ma gnctIc reg
uaator' and %, 4 compromising iieId
AS the mechanical regulators ar.
Last disappearing, and vary greatly in
"esibh, We nave not the space to :alr
them UP nov
Fig; ~ shows the principle on wbjc,
me eieGifo- magnetic regulators or.r
49, iitre YOU viii MOTTO. thar III,
bbn nFre must pass through the coil ID
the current is Rowing. tn. cdr. ar -
Mi pe magnet and Will try 10 u,iI
ao"n the button f. Now Tie erctt.r
VIII he ,he pulling power OF tho NM
net. and If Tho button is bcii @
from inc cor" by tn" spring q ,,,d !,
ms spring . IS so powerful tina, me.
the voltage is too h!gh. then ,Io rn,
TACT points Is VIII H.. closed cXr.n,in,
when the voltage is so nigh as 10 ~,
DANGEROUS TO the battery.
You Will notice also ma, in, .bu,
ne!a current must pass through Ihc
contact point. Of course. when ~, co, ,e
n rac. poin,s are open. no currcn, can
now throuEh the field and So hnr
will be no magnetic 7old be,yyn.n =,
pole pieces Of inc Generator 49,, "
no current Will be generated
Method az HcSulntinn.
AS the contact po!nt opore ti,o ~
ment the voltage generated is do hi,b
the machine viii stop gcnera,j,,,- .,,I
The voltage VIII drop The iu.,.n, ~
voltage drops the contac; nnin," III,
close again. so that they viii l.. ,n6dc
is regulated ''''N -
Where the voltage regulator is -,
t eieS. re. tnat ne'ic one, it is usually
out. ~ c"'-
BY adjusting the tension or no
spring G. tho regulator can he a, -.
give a certain maximum vultay. This
~ always done at the factory Ia
the adjustment screw should no, H..
touched except by an expert
The action of the compensatiinr nora
regulator Is shown in Fig 3. W.re
me same principle explained IN ~
cut-out lesson IS uesd bu, instead -,
operating on separator core me ac
ton takes place on the magnets ,inl5
core. and tends 10 reduce the GcId ,,I
SO the voltage. ga"
You will notice that IN .dai-io, -
the shunt field there are also
turns OF wire ia series ana liz. ~.
rAt - ~ n