Evening star. [volume] (Washington, D.C.) 1854-1972, 1920-10-31
4n.wer. to Last Week. Questions.

Answers to Last Weeks Questions.
I. The electric generator consists of
magnetic field. or magnet with
north and south pole and an armature.
The field is usually an electro mag
net, made of core of soft iron,
around which is wound many turns of
fine copper insulated wire. Between
the poles or ends of these magnets
flow lines of force, or magnetism.
similar to those Of the common horse
shoe magnet. This magnetism is nee
essary for the generator to produce
current. The armature is also core
of soft iron with wire wound around
it lengthwiSe, and revolves in the
magnetic field, cutting the lines or
force flowing between the poles. with
each half revolution. Thus is current
induced in the armature and passed
on through the outlet wires. When
the generator is first built the field
has no magnetism. 1t is run as a mo-
tor, receiving current from the out
side. which partly magnetizes the
volving as a generator the lines of
forces between the poles gradually
become stronger and reach their
maximum strength as the speed OF
the armature increases. When the
lines of force have reached their
maximum strength the current out
put of the generator will be at its
greatest, which is after hundred or
more revolutions.
2. One way Of discovering the source
through the valves or piston rings, is
to feel the crankcase after the engine
has been running. If the leak occurs
through the rings the cr3nkcase Will
be unusually warm. due to the pres
ence within of hot gases. while if the
nj the leak nCGnrS
through the valves no heat in the
crankcase will be noticeable.
3. In replacing electric headlight
bulbs: adjust them SO that point or
beam of light strikes the ground
ahead. If the bulb is placed too far
from the reflector a dark spot will
appear in the light. and If the bulb
is too close to the reflector the result
will be too wide a light and one
which will not penetrate the dark
ness any great distance away.
4. A small amount Of gasoline, II
left standing a considerable length of
time, even in a closed tank. will lose
it's igniting efficiency because of
chemical changes and evaporation.
S. Besides the numerous patent
carbon removers on the market, a
good way, and simple one. to clean
carbon from cylinder heads and tops
of pistons is to pour denatured alco-
hol into the cylinders through the
SOaIkpluS openings dllcE LILO SA6AhC
is run enough to make it warm. Run
the engine for few minutes after
the application. The alcohol softens
the carbon and tends to free 1t from
| the metal surfaces, aided by explo-
sions and exhaust strokes within the
| cylinders.
6. The most simple ignition system
| is called the make-and-break system.
With this system no sparkplugs are
! used. as the spark Is furnished by
| movable contact points within the
\ cylinder. 1t is no longer used be-
cause heat created inside the cylin-
ders soon causes these points to foul
| and burn and get out of adjustment.
| Z. If piston rings are broken. the
sparkplugs. tops of pistons and COM
F.; there will be a loss Of compression.
This leakage of compression and oil
is the result of the rings not fitting
snugly against the cylinder wall.
| s. A small amount Of back-lash or
play is to be found in the non-reversi-
bile steering gear. so that the wheels
| and tires will not be subjected to
| side strain. This type of steering gear
! will not give or allow the wheels to
! turn independently when ruts are en-
| countered on the road. so that GER
| tain amount of back-lash is necessary
to avoid wear and strain on wheels
and tires and on the steering gear it
self.
9. The high-tension magnetic and
! the electric generator diner in the
| construction of field coils. or mag
| nets. and also in armatures. The
| field and pole pieces of the generator
are not permanently magnetized
Lines of magnetic force must be built
IN when the armature begins to re-
| volye. whereas the magnetic, because
| of it's permanent magnets, can pro-
duce strong current with the hrst>
quarter-turn of the armature. AL
1 t,,rn n
| chine are wound quie similarly. the
magnetic produces alternating current,
| the generator direct current AL
ternating is changed to direct current
in the generator by means OF com
mutator whereby current which flows
| the opposition direction each half
revolution of the armature is made
to flow always in the same direction;
| With the magnetic, which is used
only for ignition. direct current is
! unnecessary, so there is no commu..
tator. but merely a collector spool
mounted on the armature smart. Both
| commutator and collector revolve
| 10 The word impulse" when ap-
| piled to engine operation means the
| force exerted on the piston when
| charge of gas is ignited within the
| cylinder. Applied to magnetic opera
+! ton, it means that period of position
| in which the armature in one revolu-
| ton reaches its maximum current
output There are two impulses in
nne revolution of the armature; there
fore two separate sparks.
This Weeks Questions.
| /. What precautions should the car
owner or operator take so that all
parts of his car will function prop
| erIy during the cold season?
.. How can rear wheel with
taper axle be removed if the wheel
sticks tightly to the axle?
3 Why should not any kind of
| water he used in the cooling system?
T. How is the word Chassis pro-
nounccd and from what is 1t derived?