Lcece-Neville Internal Circuits, Cutout and Generator, Motor and Gener-
ator with Cutout 726
National Standard Wiring 727
North East Internal Circuits, Models A A B 72N
North East Internal Circuits, Models GAD 729
North East Internal Circuit, Model L, Generator, Ground Return
System 730
North East Internal Circuit, Model H, K or R, Starting Motor 731
Philbrin Duplex Ignition System, Internal and External Wiring 732
Remy Internal Circuits 733-736
xxv
STANDARD AND INTERNAL DIAGRAMS Continued
System
Diagrams of
Page
Rushmore
Simms-Huff. . . .
Simms-Huff. . . .
Splitdorf
Splitdorf
Splitdorf
Splitdorf-Apelco
Splitdorf-Apelco
U. S. A. Liberty Ignition
U. S. L...
Wagner.
Wagner.
Wagner .
Wagner
Wagner-Ward-Leonard
Ward-Leonard .
Ward-Leonard .
Westinghouse . .
Westinghouse .
Standard Wiring .- 737
Internal Circuits 738
12 Volt, Motor Generator, Internal Circuit 739
Generator and Regulator, Internal Circuit _. . .740
Internal Circuit, Motor Generator, Switch and Cutout. . . . 741
Internal Circuit, Generator and Regulator TU-1 742
Internal Circuits, Generator with Cutout, Generator with
Regulator 743
Internal Circuits, 12 volt, Motor Generator with Cutout .... 705
1919-1920, Aviation Circuit Diagram 742
Internal Circuits, 12-24 Volt, External Regulator, External
Armature Type 744
Internal Circuits, Motor and Generator with Regulator . . . 666
Internal Circuits, EM-165 Generator with Cutout 696
Internal Circuits, 12 Volt, Single Unit, Motor Generator,
Early Models 745
Internal Circuits, Model 36-T Motor, Model 45-T Generator. 746
6-12 Volt, Two Unit as Installed on Various Motor Cars and
Trucks not originally equipped 747
Internal Circuits, Voltage Regulators 748
Internal Circuits, Generator with Regulator Cutout 749
Internal Circuits, Connections for Separately Mounted
Regulator 750
Internal Circuits, Connections for 3rd Brush Gen. and Self
Contained Cutout, Starting Motor, Starting Switch . . .751
System
Diagrams of
Page
Westinghouse Standard Wiring, Connections of Complete System with
Separately Mounted Regulator 752
Westinghouse Standard Wiring, Showing Single Reduction Motor and
Vertical Ignition System 753
Westinghouse Internal Wiring and Mechanical Connections of Double
Reduction Motors and Switch for Automatic Screw
Pinion Shift 754
Westinghouse Internal Ignition Circuits, Horizontal Ignition System,
Vertical Ignition System 755
Westinghouse Internal Circuits, 3rd Brush Generator with Separate Cut-
out, Starting Motor and 3rd Brush Generator with Self
Contained Cutout 756
Westinghouse Internal Circuits, Generator Frame Nos. 150 and 750 (R. H.
Rotation) 757
Westinghouse Internal Circuits, Motors, Generators, Switches, Relay
Regulators, Cutouts, etc 758-763
Westinghouse Round Generator with Separate Regulator, Vertical Ignition
SGL Reduction Motor, Ammeter, Fuse Block, Starting
Switch, Rev. Lighting and Ignition, Switch 764
Westinghouse Standard Motor, Lighting and Ignition Generator, 2-Gang
Lighting and Ignition Switch, Ammeter, Fuse Block. . .765
Westinghouse 3rd Brush Generator, Separate Cutout, Starting Motor,
Starting Switch 766
Westinghouse Lighting and Ignition Frame No. 760, (R. H. Rotation) 767
Westinghouse Starting Motor Connections 768
if either or both are effected by short circuit, open circuit,
poor contact, or ground, the strength of the machine will be
reduced proportionately.
GENERATORS AND IGNITION COILS
One of the fundamental principles of electricity is that if
the number of magnetic lines of force passing thru any closed
coil or closed electrical circuit be changed, a voltage will be
induced in this coil which will cause a current to flow, the
magnetic effect of which is to oppose the change in the orig-
inal number of lines of force. The voltage, as induced, depends
upon the length of time required to change the magnetic influ-
ence, the more rapid the change, the higher the voltage. The
operation of all direct current generators, as well as gasoline
motor ignition systems, depends upon this principle.
In the case of the generator, the number of magnetic lines
of force threading any coil of the armature is a maximum
when the plane of the coil is at right angles to the path of the
field force from the field coils. This can be readily seen if we
take, as an example, a two-pole generator with a single coil
on the armature. If we imagine the poles to be in the hori-
zontal position and the plane of the coil in the vertical position
we have a condition of maximum number of lines of force
threading the coil. Now, if we turn the coil thru any appreci-
able angle, the field coils and pole pieces remaining stationary,
the number of lines of force is decreased and a voltage is gener-
ated (the amount depends upon the speed of rotation) in the
coils of the armature. By increasing the number of coils in
the armature the voltage is increased and kept more nearly
constant.
The commutator on the end of the armature shaft is for
reversing the current as it leaves the armature, since it is a
fluctuating or alternating current that is generated in the
coils. This can be readily seen because the number of lines of
force is increased during one-half of the revolution and de-
creased during the other half.
In the case of ignition systems, we have a similar con-
dition, namely, the change in the number of lines of force
threading the coil. Ignition coils, primary and secondary,
are wound about the same iron core so that any change in
magnetic influence of one is transmitted directly to the other
with a minimum of loss. When current is flowing thru the
primary or low voltage coil of the system, from a battery, in
the case of battery ignition, and self-generated by the mag-
nets, in magneto ignition, it builds up a heavy magnetic field,
the lines of force of which thread the secondary. When this
current is cut off by the opening of the breaker points, this
magnetic influence ceases. The change in the number of lines
of force thru the primary causes a countervoltage to be
induced in the primary, the current from which must be
absorbed or a bad arc develops at the breaker points. The
condenser, a vital part of all ignition systems, is employed for
this work, as further described herein.
Inasmuch as both the primary and secondary coils are
wound on the same core, the effect of the change in the magnet-
ism of the primary has the same result in the secondary in
that a voltage is induced. The coil relationship is such that
this secondary voltage is very high and forces itself across
the gap of the spark plug, causing the ignition spark.
IT ION
The internal combustion motor derives its power from
the expansive force developed by the charge of gas which is
compressed in the explosion chamber being suddenly raised
i a low to a high temperature. To raise the temperature
df this gas one must supply heat This heat is generated by
burning of a part of the gas (gasoline) which is com-
ised. As in the case of any burning material, a definite
length of time is required, depending upon the quantity,
before the material is entirely consumed. This last statement
must be borne in mind at all times when considering ignition
problems.
To start the burning of any combustible substance an ignit-
ing flame or its equivalent, the heat value of which is measured
by the inflammability of the substance, must first be applied.
This igniting flame, in the case of the gas in an automobile
engine, is supplied by the spark which occurs between the elec-
trodes of the spark plug. It is very essential that this spark
occur at the proper time relative to the position of the piston
in the cylinder as .well as that the valves be in the proper
position. The gas must be compressed to its highest point
when the combustion is completed. AVere there no time ele-
ment to be considered in the burning of the gas, ignition could
take place when the piston is at its highest point. However, in
order to have the motor operate at its proper efficiency, the
spark is so set that the charge is ignited before the piston
reaches the top dead center. Since the amount of this advance
of the spark before center depends on the speed of the motor
as well as its load, considering all forms of ignition the same,
provision both manual and automatic is made for varying the
sparking position. If the ignition takes place too early, the
motor will have a knock that is very characteristic, whereas
it' it be too late, loss of power and excessive heating will be
noted.
In the majority of battery ignition systems the breaker
cam is held to the drive shaft with some form of friction
device. This cam can be easily moved and thus change the
sparking position beyond the limits of the control lever. In
the high tension magneto the breaker mechanism is perma-
nently located on the armature shaft, usually with some form
of key. For this reason the only method of altering the spark-
ing position beyond the range of the control lever is thru the
driving yoke or timing gears of the motor. Alteration of the
relationship between the distributor gear and armature gear
does not affect the sparking position of the magneto, but does
move the high tension conductor relative to the segments in
the distributor when the magneto spark occurs..
There are at present two distinctive types of ignition in
use on automobile engines, namely, battery ignition and mag-
neto. The principle of operation of each is the same and it is
identical with that of the generators, i. e., the inducing of a
voltage in a coil of wire by changing the number of magnetic
lines of force threading the coil. The ignition system is made
up of a primary and a .s> <<> mlnri/ coil, a primary circuit
breaker, a condenser and a distributing system for both the
primary and secondary current. The primary coil is one of
a comparative few number of turns of rather heavy wire
wrapped around a core of soft iron. This coil, as its name
implies, is 'the first one to function in the operation of the ,
ignition system. The secondary coil is composed of a greater
number of turns of very small wire. Since the secondary
coil depends upon the changes in the magnetic influence of the
primary coil, and in order to eliminate as much as possible
the loss of this magnetic influence thru leakage, both the pri-
mary and secondary coils are wound upon the same core.
The primary circuit breaker is a mechanism used for opening
the primary circuit at regular predetermined intervals. The
condenser functions in the ignition system in the same way as
an air chamber on a water pump, that is, it absorbs the surge
in the pressure at one interval and discharges the accumulated
pressure at another interval. An electrical condenser is made
up of a number of sheets of electrical conducting material,
usually tin or aluminum foil, separated by sheets of insulating
material, such as paper or mica. Its complete operation is
outlined below. The primary distribution system, in the case
of battery ignition, is that set of wires which feed the primary
current from the battery to the coil and breaker points, and in
the magneto that wire or system of wires which are used to
short circuit the magneto primary circuit breaker and thus
make it inoperative. The secondary distribution system is
that which distributes the secondary or high voltage current
from the secondary coil to the spark plugs. In the case of
multi-cylinder motors this secondary distribution system usu-
ally takes the form of a distributor head moulded from a high
tension insulation with inserts moulded in place. The high
tension current is fed to the center of the distributor head
and thru some form of rotor distributed to these inserts and
from them thru the spark plug wires to the plugs.
-In both the single spark battery ignition and high tension
magneto ignition the primary coil is first energized, its mag-
netic field encircling and threading the secondary 'coil. Upon
opening the circuit of the primary coil this magnetic influence
ceases, which induces a high voltage in the secondary coil.
In the design of the ignition unit the relationship between
the primary and secondary coils is such that this induced
voltage is sufficient to jump the gap at the plug. At the time
of opening the primary circuit there is a considerable voltage
induced in the primary coil itself and this voltage tends to
force current thru the gap at the breaker points even after
they have been slightly opened. Were this condition allowed
to exist the breaker points would very soon burn away. It
is at this point that the condenser functions. Instead of the
arc forming at the breaker points the condenser, thru what
we may term its elastic characteristic, absorbs the current
from this self-induced voltage and almost immediately dis-
charges it back thru the primary coil. Since a reversal of
the direction of flow of the current reverses the direction of
flow of the magnetic lines of force, the discharge of the con-
denser reduces the length of time required for the number of
lines of force threading the secondary coil to change from
maximum to zero. This reduction of the time element for
the change increases the secondary voltage because the induced
voltage in any coil depends upon the time rate of change of
the magnetic influence threading the coil.
The action of the high tension magneto is identical with
that of the battery ignition, altho the resultant operating
characteristics differ. The high tension magneto, being a
self-contained unit, develops its own primary energy thru the
rotation of the armature between the poles of the strong
horse shoe magnets. The generation of this primary current
is explained by again referring to the topic of generators in
that the number of magnetic lines of force is changed by the
rotation of the armature in the magnetic field. The primary
XXXI 1
iker of the high tension magneto is so located that
tlu- contact points open when the primary current is at its
ttest value. The magneto armature, under this condition,
-ually from one-eighth to live-thirtyseconds of an inch of
leaving the pole shoe, when the spark control lever is in the
fully retarded position. Since the primary voltage, together
with the primary current, increases with an increased speed
tat ion of the armature, it is possible to break the primary
nit earlier in the relative position of armature and pole
pit
There is otic characteristic in high tension magneto ignition
that is not found in battery ignition, due to the rotation of
the secondary coil in the magnetic field. This causes what is
called the "after burning" of the spark. Also, since the cur-
rent as generated in the primary coil of the magneto is alter-
nating, the direction of flow thru the breaker points is reversed
\ time that they separate. This fact reduces the tendency
of burning of the points and eliminates the formation of a
cone and crater condition which is so often found on battery
iirnitioii systems which have no current reversing feature
rporated in the ignition switch.
A cutout consists of an iron core having two windings
thereon, namely, a shunt and a series winding. The shunt
winding is connected across the generator so as to receive the
1'u 11 voltage of the generator across the terminals, and when
the machine attains a speed at which it develops a voltage over
that of the battery, the shunt winding is sufficiently energized
to close the cutout. When the cutout is closed a small current
is caused to flow in the series winding connected in the main
circuit from the generator to the battery, and this coil is ener-
gized. The pull due to the series winding, which is much
greater than that of the shunt, reinforces the pull due to the
shunt winding and firmly holds the contacts of the cutout in
their closed position.
When the speed of the generator is decreased to a value at
which its voltage is lower than that of the battery, or when
the generator is at rest, a momentary discharge of the battery
thru the series winding takes place and demagnetizes the coil.
The instant the coil is demagnetized, the tension spring
attached to the cutout pulls its contact arm away from the
core and opens the circuit.
i'1'TOUTS OR REVERSE CURRENT RELAYS
The cutout or reverse current relay automatically connects
and disconnects the generator to the battery. When the gen-
erator is at rest, the contacts are hold open by a tension spring
on one of the cutout, contacts. When the generator attains
a speed sufficient to develop a voltage of 6.5 volts, in the case
of 6-volt systems, the cutout is automatically closed and the
generator is connected to the battery.
VOLTAGE REGULATORS
Most voltage regulating units consist of a core having a
single winding, this winding being connected across the gener-
ator. The current in the winding and the resulting magnetic
pull of the core will depend upon the pressure developed by
the generator. Opposite one end of the core is a vibrating
reed or contact arm, which is spring retracted away from the
XXXI 1 1
core. When this reed is spring retracted away from the
core it makes contact so that there is a by-pass aro*und a
resistance coil, which is in series with the field winding of the
generator. With the vibrating reed in this position, the shunt
field winding receives the full pressure developed by the gen-
erator. With increasing generator speed the voltage increases
until the armature develops 7.75 volts, in case of a 6-volt
system, and at this electrical pressure the regulator begins to
function and will maintain 7.75 volts across the generator
brushes at all higher speeds.
With increasing generator speed the voltage will tend to
rise above 7.75. If, however, this value is exceeded by a very
small amount, the increased pull on the vibrating reed of the
regulating unit will overcome the spring pull and it will be
drawn towards the core, thus opening the contacts and insert-
ing the resistance in the generator field circuit. The added
resistance in the field circuit decreases the exciting current
in the field winding and the voltage developed by the armature
tends to drop below the normal value of the 7.75 volts. If
the voltage drops slightly below the normal, the pull of the
spring on the regulator reed predominates and it again moves
away from the core and closes the contacts which short cir-
cuits the resistance and permits the exciting field current to
increase. This cycle of operations is repeated at rapid inter-
vals and maintains the generator voltage constant at all speeds
above the critical value at which it develops 7.75 volts with
the resistance cut out of the field circuit.
The rapidity of vibration depends, to a large extent, upon
speed, the regulator reed vibrating one hundred to one hun-
dred and fifty times per second. The actual voltage developed
by the generator is made up of a series of very fine ripples
above and below a straight line, the mean value of these rip-
ples being 7.75 volts, the constant value for which the regulator
is adjusted.
CONSTANT CURRENT GENERATORS. (Third brush
regulation)
The voltage regulation of all third brush generators is
effected by means of the reactive magnetic flux set up by the
current flowing thru the armature.
The amount of current generated depends primarily upon
the speed at which machine is driven and the position of the
regulating brush with respect to the two main brushes.
Beginning at zero speed, the voltage is, of course, zero, and
with increasing speed the voltage increases until the armature
develops 6.5 volts, at which value the shunt coil of the cutout
is sufficiently energized to cause the cutout switch to close.
After the cutout is closed, the generator begins to deliver
current to the battery.
The constant current generator has a single shunt winding
distributed over its poles and the regulation is effected by
having this winding connected between one of the main gener-
ator brushes and an auxiliary or regulating brush. The
maximum current generated depends upon the location of
the third brush with respect to the main brush to which one
side of the shunt field is connected. Moving the third, or
regulating brush, in the direction of rotation of the armature,
increases the generator output, and in direction opposite to
the rotation of armature decreases the output.
LOCATION AND CORRECTION OF FAULTS
To be able to fully understand and intelligently trace the
faults or trouble that occur from time to time in the electrical
;its and equipment on motor cars, it is essential that the
iianic be- able to read the blue-prints covering their electrical
wiring. Many equipment and motor car manufacturers iuc
instruction books containing prints covering their electrical
equipment, but as a rule these are so small and the lines repre-
;ng tin- wires are so close together that it is impractical to
d hours in tracing them out. To enable the user of this
Manual to render service on the electrical equipment of motor
with the fullest possible efficiency, we have compiled and
laid out in plainly readable blue-prints wiring diagrams of all
and the internal circuits of their various electrical units.
The wiring diagrams contained in the instruction books of
the various motor car manufacturers are drawn to scale, which
Drawing No. 1
Drawing No. 2
means a comparatively large starting motor and generator, and
a very small lighting and ignition switch. In the following
blue-prints the publishers have not attempted to make drawings
to scale, but have placed the units in as nearly as possible to their
positions on the car, as is practical, and have also enlarged such
units as coils, switches, circuit breakers, etc., which have many
wires leading to them, thereby making the tracing of circuits an
easy matter. The accompanying illustrations represent the
wiring of the same car drawing No. 1, which shows a perspective
view, is drawn more or less to scale with units placed in their
exact position, while drawing No. 2 is laid out flat and with
emphasis made to the units which have the greater number of
wires leading to them.
In tracing electrical troubles from wiring diagrams always
bear in mind the fact that it is necessary to have a complete
XXXV
circuit in order that a current may flow; also that if any circuit
is crossed with another circuit or comes in contact with the
ground (or car frame in the case of a single wire system) this
constitutes a short circuit, or a direct path other than the one
originally intended, through which the full force of the current
will flow and which usually results in a certain portion of the
wiring being burned out. Take for example drawing No. 2:
should wire "A" come in contact with the ground (or return
circuit) at point marked "B", a short circuit would result and the
full force of the current from the battery would flow from the
negative post of the battery through wire "A" to point "B" and
return through the ground "G", with the result of burning cable
"A." Or, should cable "A" have sufficient carrying capacity
to carry the load, the battery would become discharged in a very
short time. In case of lighter wires, or those having less carry-
ing capacity, as in wire "C," should it come in contact with the
ground circuit at point "D",the result would be that wire "C'
would become so hot that the insulation would burn off and the
wire would burn or become disconnected. Should the ground
occur at point marked "E", the current would flow from the
battery through wire "C" to horn, through horn to point "E,"
returning to the battery through the ground circuit, with the
result that the horn would blow until ground connection at
point "E" was disconnected or the positive or negative terminal
lead was disconnected from the battery. Should wire "F"
become broken or poor electrical contact occur at any point
from the switch to the ignition coil, the result would be an open
circuit, thereby making it impossible for current to flow from the
battery through ignition switch (in "on" position) to ignition
coil.
To trace a circuit, taking for example that of the headlights,
in illustration No. 2: begin at the battery, following the main
lead to the starting switch, and from there back through the am-
meter, through fuse to lighting switch, through lighting switch,
through wire "G" to head lamps, through head lamp bulbs to
frame of car and through frame of car to battery.