Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1919-06-22
.SIMPL|F|ED LESSONS IN
CARE OF AUTOMOBILE
Starting Motor Subject of ENper
Gucrlick's Weekly Automobile
Dissertation.
PRINCIPLE OF oPERAT1o i
When Current Flows Through Wire
u. Loop Of Wire III Field, Loop Will
Be Made to Rcvolve Ont of
Field.

We have seen how when a loop OF
wire is made to revoive in magnetic
in the wire. Now the reverse action
VIII also take place; that is. when a
cnrrsnt OF electricity is made TO flow
the loop viii he made 10 revolve out OF
the field. In tho first case Cthe genera
.or) by, revolvins the loop OF wire in
wire; in the second case cine motor.
by making current flow through the
wire the loop is made TO revolve out
OF the field. On the latter principle all
electric motors are designed.
Thus an electrical cengior can be
made to act as a motor, or a motor as
There is. however. a practical diner
ence in the two machines. The proper
lions are different, but the greatest
coils. In the las. lesson YOU we're
shown how the field coils Of the genera
tor are shunt wound or compound
tically always series wound: that is
the current As il comes from the bat
terry first passes through the field coils,
then through the arInature winnings
and then back 10 the battery. Thus
you see. the coils and armature are
in a series.
High AmpcrnEc Required.
IT requires high amperage 20 give
TO crank the heavy engine. ranging
from 100 to SOC depending upon the
size OF the motor, the size OF the engine
and the gear ratio between them.
It is important 10 remember the
above, as not only does II show how
the battery is quickly discharged when
planned in the battery lesson. but it
shows why great care must he taken
not TO get any other units OF the start
ing and lighting system, in series with
the starting motor, asd why tho wires
leading to the starting motor and the
starting switch must be largo The
generate Iig ,:,, isnition; amme ter:
amperage. oeldom higher than Is. an"
should tho high ampcraEc motor cur
rent flow through them they would in
stantly he burned out and ruined
The above mistake is seldom made
where the generator and motor are
two separate units, but, is very often
made where they are built together
ammctcr on his car TO tell him the
condition Of tho charging Of his bat
terry. and has gotten ii in series with
the motor. with the result that ii was
instantly burned out
The fact that n motor will act as a
generator or generator as motor is
utilized in many cases the two instru-
ments being built together. When SO
built together 1t is known as a motor
generator. and the car is SAID to be
equipped with single unit while
when the two are separate. 1t is said
to be a two-unit system.
Motor-Gcncrntor Designs Wary.
The designs OF tho motor-generators
vary. In some cases the machine has
two Commentators. two armaturc wind
ings and two field windinGs, others
have but one commutator. but two sets
of brushes. while still others have onlA
two field windings; series, to be used
when the machine acts as motor, ant
a shunt. TO be used when it acts as &
generator.
The motor seldom gives trouble, wha,
troubles II is subject TO being abou'
the same as those Of the generator
Placing too great load upon the
motor, as is sometimes done by usng
the motor while the car is in gear. sc
that in addition to crankinS the en-