5ME6.

2A : AUTOMOBILE ENGINEERING

GWECA
Ajmer, India
305002 UNIT : 4
IGNITION SYSTEM

Submitted by :
Shreya Kanwar (16EEMME023)

Submitted to:
Dr. Jai Gopal Gupta
Head and asst. prof.
5ME6.2A Department of Mechanical Engineering
GOVERNMENT WOMEN ENGINEERING COLLEGE AJMER
 INTRODUCTION
• The system in an internal combustion engine that
produce the spark to ignite the mixture of fuel and
air: includes the battery, ignition coil, distributor,
spark plug and associated switches and wiring is
called ignition system.
• Produces high voltage arcs at the spark plug
electrode.
• These high voltage produce by ignition coil, which is
supplied with lower voltage battery.

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 Continue…..
• The combination of all the devices required to
produce an electric spark of desired intensity and at
proper moment is called spark ignition system.
• The spark must occurs towards the end of
compression stroke.

5ME6.2A AUTOMOBILE ENGINEERING

 FUNCTION OF AN IGNITION SYSTEM
• Produces 30,000 volt spark across spark plug.
• Distributes high voltage spark to each spark plug in
correct sequence.
• Times the spark so it occurs as piston is nearing top
dead centre.
• Varies spark timing with load, speed and other
conditions.

5ME6.2A AUTOMOBILE ENGINEERING

 REQUIREMENTS OF AN IGNITION
SYSTEM
• It should provide a good spark between the
electrodes of the plugs at the correct timing.
• The duration of the spark must be long enough with
sufficient energy to ensure that ignition of the
mixture has a high chance of occurring.
• The system must distribute this high voltage to each
of spark plugs at the exact time in every cycle i.e. it
must have in it a distributing device.
• It should function efficiently over the entire range of
engine speed. It should be light, effective and reliable
in service.

5ME6.2A AUTOMOBILE ENGINEERING

 TYPES OF IGNITION SYSTEM
• CONVENTIONAL IGNITION SYSTEM.
• ELECTRONIC IGNITION SYSTEM.
• PROGRAMMED IGNITION SYSTEM.
• DISTRIBUTORLESS IGNITION SYSTEM.

5ME6.2A AUTOMOBILE ENGINEERING

 CONVENTIONAL IGNITION SYSTEM
• Basically Convectional Ignition systems are of 2 types
(a) Battery or Coil Ignition System, and
(b) Magneto Ignition System.
• Both these conventional, ignition systems work on
mutual electromagnetic induction principle. Battery
ignition system was generally used in 4-wheelers, but
now-a-days it is more commonly used in 2-wheelers
also (i.e. Button start, 2-wheelers like Pulsar, Kinetic
Honda; Honda-Activa, Scooty, Fiero, etc.).

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 Continue …
In this case 6 V or 12 V batteries will supply necessary
current in the primary winding.
• Magneto ignition system is mainly used in 2-
wheelers, kick start engines. (Example, Bajaj
Scooters, Boxer, Victor, Splendor, Passion, etc.). In
this case magneto will produce and supply current to
the primary winding. So in magneto ignition system
magneto replaces the battery.

5ME6.2A AUTOMOBILE ENGINEERING

 BATTERY IGNITION SYSTEM
• Battery Ignition System is used in automobile to
produce spark in the spark plug for the combustion
of fuel in the I.C. engine. Here the main source for
the spark generation is the battery.
• Main parts
• The main parts of battery ignition system are
• 1. Battery
2. Ignition switch
3. Ballast resistor
4. Ignition coil

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5. Contact breaker
6. Capacitor
7. Distributor
8. Spark plug

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5ME6.2A AUTOMOBILE ENGINEERING
 Battery ignition system components
• BATTERY:- A battery is used to provide energy for
ignition. It is work as storage of energy and charged
by dynamo, which is driven by engine. It converts
chemical energy to electric energy. Two types of
battery used in spark ignition system, lead acid
battery and alkaline battery. The first one is used in
light duty commercial vehicle and the other one is
used in heavy duty commercial vehicle. It is housed
in primary side of ignition coil.

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 Continue…
• IGNITION SWITCH:- It is a switch which is used to
turn ON or OFF ignition system. One end of ignition
switch is connected to battery and other with
primary winding of ignition coil through ballast
resistor.
• BALLAST RESISTOR:- It is linked in series with primary
winding and it is present in between ignition switch
and ignition coil. It is used to prevent injury due to
overheating due to primary winding of ignition coil.
Also, it controls current passes through primary
winding and it also made by iron.

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 Continue …
• IGNITION COIL changes battery voltage to 30,000v
during normal operation.
• CONTACT BREAKER:- This is a mechanical device
making and braking the primary circuit to ignition
coil. When the points are closed current flow in
ignition coil and when it open, flow of current
stopped.
• DISTRIBUTOR :- It causes the spark to occur at each
plug earlier in the compression stroke.
• SPARK PLUG uses high voltage from ignition coil to
produce an arc in the combustion chamber.

5ME6.2A AUTOMOBILE ENGINEERING

5ME6.2A AUTOMOBILE ENGINEERING
 WORKING
• In the Battery ignition system as the ignition switch is
ON, the current from the battery starts to flow
through the primary circuit through ballast register,
primary winding and contact breaker.
• The current flowing through the primary winding
induces magnetic field around it. The more will be
the current, the stronger will its magnetic field. As
the contact breaker opens, the current through the
primary winding collapse and this immediate
collapse in the current induces a voltage of about
300V in the primary winding.
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 Continue ….
This voltage induced in the winding charges the
capacitor to the much greater voltage than the battery.
As the capacitor charged, the current through the
primary winding stops and the current starts to flow to
the battery form the capacitor. This reverses the
direction of current and magnetic field in the primary
winding. Due to the collapsing and reversing of the
current and magnetic field, a very high voltage of about
15000 to 30000 V induced in the secondary winding.
• The high voltage current induced in the secondary
winding is transferred to the distributor through a high
tension cable.
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 Continue…
• The distributor has a rotor that rotates inside the
distributor cap. The distributor cap has metallic
segments embedded into it. As the rotor rotates, it
presses and opens the contact breaker point. This
allows the high tension current to transfer to the
spark plugs through the metallic segments.
• As the high tension current reaches the spark Plug, it
produces spark in the engine cylinder for the
combustion of the air-fuel mixture.

5ME6.2A AUTOMOBILE ENGINEERING

 Advantages
 At the time of starting or at low speed good spark is
available.
 The battery which is used to generate spark can be
used to light other auxiliary like headlight, tell light
etc.
 Initial expenditure is less and it has low maintenance
cost.
 Ignition system is not affected by adjusting spark
timing in battery ignition system.

5ME6.2A AUTOMOBILE ENGINEERING

 DISADVANTAGES
 Time available of built up the current and stored
energy is decrease as speed of engine increases.
 Contact breaker subjected to both electrical and
mechanical wear which results short maintenance
interval.
 The primary voltage decreases as the engine speed
increase. So it is not fully reliable of high speed
engine.

5ME6.2A AUTOMOBILE ENGINEERING

 MAGNETO IGNITION SYSTEM
• Magneto ignition system is a special type of ignition
system with its own electric generator to provide the
required necessary energy for the vehicle
(automobile) system. It is mounted on the engine
and replaces all components of the coil ignition
system except the spark plug. A magneto, when
rotated by the engine, is capable of producing a very
high voltage and doesn’t need a battery as source of
external energy.

5ME6.2A AUTOMOBILE ENGINEERING

 Magneto ignition system components
• Magneto:-It is the major part of this type of ignition
system because it is source of energy. A magneto is a
small electric generator which is rotate by the engine
and is capable of produce a very high voltage and
does not need battery as a source of external energy.
The magneto contains both primary and secondary
winding thus it does not require a separate coil to
boost up the voltage required to operate the spark
plug. There are two types of magneto. First one is
known as armature rotating type and other one is
known as magnet rotating type.
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 Continue…
In the first type, the armature rotates between the
stationary magnate. On the other hand in second
type armature is stationary and the magnates are
rotating around armature.
• Distributor:- The distributor that is used in the
Magneto Ignition System is also used in the multi-
cylinder engine. The multi-cylinder engine is used for
regulation of spark in a correct sequence in the spark
plug. The surge of the ignition is distributed
uniformly among the spark plugs. There are two
types of distributors
 Carbon brush type distributor
 Gap type distributor

5ME6.2A AUTOMOBILE ENGINEERING

 In carbon brush type, the rotor arm sliding over the
metallic segment carry the carbon brush which is
embedded inside the distributor cap or molded
insulating material. This help to provide an electric
connection with the spark plug.
In gap type, the distributor electrode of rotor
arm is close to the distributor cap, but no contact is
made leading no wear for the electrode.

5ME6.2A AUTOMOBILE ENGINEERING

 SPARK PLUG

• A spark plug generally has two electrodes which are

separated with each other. A high potential discharge
flow through it which generate spark and ignite the
combustion mixture in cylinder. It mainly consist two
electrodes a steel shell and an insulator. The central
electrode connected with the supply of ignition coil. It
is well insulated with the outer steel shell which is
grounded. There is a small air gap between steel shell
and central electrode, between which spark is
generated. The electrode usually made by high nickel
alloy so it can withstand with high temperature and
corrosion resistance.
5ME6.2A AUTOMOBILE ENGINEERING
 Capacitor:

• The capacitor used in the Magneto Ignition System is

a simple electrical capacitor in which two metal
plates are separated by an insulating material with a
distance. Commonly, air is used as insulating
material, but for a particular technical requirement,
some high-quality insulating material is used.

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5ME6.2A AUTOMOBILE ENGINEERING
 WORKING
• The working principle of the this ignition System is similar
to the working principle of coil or battery ignition system
except that in it magneto is used to produce energy but
not the battery. Here are the following scenarios that
occur in it.
 When engine in the system starts it help magneto to
rotate and thereby producing the energy in the form of
high voltage.
 The one end of the magneto is grounded through
contact breaker and ignition capacitor is connected to it
parallel.
 The contact breaker is regulated by the cam and when
the breaker is open, current flows through the condenser
and charges it.
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 Continue…
 As the condenser is acting like a charger now, the
primary current flow is reduced thereby reducing the
overall magnetic field generated in the system. This
increases the voltage in the condenser. This increased
high voltage in the condenser will act as an EMF thereby
producing the spark at the right spark plug through the
distributor.
 At the initial stage, the speed of the engine is low and
hence the voltage generated by the magneto is low but
as the rotating speed of the engine increases, it also
increases the voltage generated by the magneto and flow
of the current is also increased. To kick start the engine,
we can use an external source such as the battery to
avoid the slow start of the engine
5ME6.2A AUTOMOBILE ENGINEERING
5ME6.2A AUTOMOBILE ENGINEERING
 Advantages and Disadvantages:

• ADVANTAGES :-
 This system is more reliable at medium and high speed.
 It is more reliable because no battery is used.
 It requires less frequently maintenance.
• DISADVANTAGES :-
 It has starting problem due to low cranking speed at
starting.
 It is more expensive compare to battery ignition system.
 There is possibility of misfire due to leakage because
wiring carry vary high voltage.

5ME6.2A AUTOMOBILE ENGINEERING

 ELECTRONIC IGNITION SYSTEM
• In internal combustion engine, combustion is a
continuous cycle and occurs thousands time in a
minute so a effective and accurate source of ignition
is required. The idea of spark ignition came from a
toy electric pistol that used electric spark to ignite a
mixture of hydrogen and air to shoot a cork.
• Electronic ignition system is the type of ignition
system that uses electronic circuit, usually by
transistors controlled by sensors to generate electric
pulses which in turn generate better spark that can
even burn the lean mixture and provide better
economy and lower emission.

5ME6.2A AUTOMOBILE ENGINEERING

 MAIN COMPONENTS
 Battery :- It is the powerhouse of the ignition system
as it supplies the necessary energy to the ignition
system same as battery coil ignition system.
 Ignition Switch :- it is the switch used in ignition
system which governs the ON and OFF of the system
same as the battery coil ignition system.
 Ignition control module :- It is the brain or
programmed instruction given to the ignition system
which monitors and control the timing and intensity
of the spark automatically. It is the device that
receives voltage signals from the armature and set
the primary coil to ON and OFF ,it can be placed
separately outside the distributor or can be place in
electronic control unit box of the vehicle.

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 Armature :- Contact breaker points of
battery ignition system is replaced by an armature
which consists of a regulator with teeth (the rotating
part), vacuum advance and a pickup coil(to catch the
voltage signals),Electronic module receives the
voltage signals from the armature in order to make
and break the circuit, which in turn sets the timing of
the distributor to accurately distribute current to the
spark plugs.
 Ignition coil :- Same as the battery ignition coil
system ignition coil is used in electronic ignition
system to produce high voltage to the spark plug.

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 Continue …
 Ignition distributor :- As the name indicates it is the
device use to distribute the current to the spark
plugs of the multi cylinder engine.
 Spark plug :- Spark plug is used to generate spark
inside the cylinder.

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5ME6.2A AUTOMOBILE ENGINEERING
 WORKING
• When the driver switch ON the ignition switch in
order to start a vehicle the current starts flowing
from the battery through the ignition switch to the
coil primary winding, which in turn starts the
armature pickup coil to receives and send the voltage
signals from the armature to the ignition module.
• When the tooth of the rotating reluctor comes in
front of the pickup coil as shown in the fig the
voltage signal from pickup coil is sent to the
electronic module which in turn senses the signal
and stops the current to flow from primary coil.
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 Continue …
• When the tooth of the rotating reluctor goes away
from the pickup coil, the change in voltage signal is
sent by pickup coil to the ignition module and a
timing circuit inside ignition module turns ON the
current flow.
• A magnetic field is generated in the ignition coil due
to this continuous make and break of the circuit
which induced an EMF in secondary winding which
increases the voltage upto 50000 Volts.
• This high voltage is then sent to distributor ,which
has the rotating rotor and distributor points which is
set according to the ignition timing.
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 Continue …
• When the rotor comes in front of any of those
distributor points the jumping of voltage through the
air gap from the rotor to the distributor point takes
place which is then sent to the adjacent spark plug
terminal through the high tension cable and a
voltage difference is generated between the central
electrode and ground electrode which is responsible
for generating a spark at the tip of the spark plug and
finally the combustion takes place.

5ME6.2A AUTOMOBILE ENGINEERING

 Application

• Electronic ignition system is used in modern and

hyper cars like Audi A4, Mahindra XUV-500, etc. and
bikes like ktm duke 390cc,Ducati super sports etc. to
meet the high reliability and performance need .
It is also used in aircrafts engine due to its better
reliability and less maintenance.

5ME6.2A AUTOMOBILE ENGINEERING

 Previous year
question of RTU examination
1. Explain the Battery lgnition system with the help
of neat sketch Compare its advantages and
disadvantages with that of Magneto Ignition
system. (2015)
2. With help of neat sketch explain working and
construction of magneto ignition system.(2017)
3. Explain the working of the ignition system for a
four cylinder passenger car engine with the aid
of a schematic diagram.(2012)

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 Continue …
3. Give a neat sketch of magneto ignition system for a
4- cylinder engine and describe how does it work.
(2012)
4. Write short notes on following :
a) Function of distributor in the ignition system.
b) Contact breaker.(2012)

5ME6.2A AUTOMOBILE ENGINEERING

 Thanks

5ME6.2A AUTOMOBILE ENGINEERING