battery ignition system

ASEMINAR ON

BATTERY IGNITION SYSTEM

Index

Objective Construction Working Advantages Disadvantages Applications Conclusion

Objectives

To understand the construction and working of a battery ignition

system.

To locate and identify parts of a battery ignition system.

To know the application, merits and demerits of a battery ignition

system.

Construction

It consists of the following parts:Battery(Lead Acid type) Stores the Electrical Energy. Charges using the Dynamo

driven by the engine

Ignition switch Helps in turning the

system ON or OFF

Ballast Resistor Under prolonged conditions it

helps to maintain the temperature of Ignition Coil

Ignition coil Steps up the Low Voltage to High

Voltage to induce an electric spark in the spark plug.

Contact breaker Making and breaking

the primary circuit.

Capacitor Prevents the burning and possible

welding of metal points.

Distributor Distributes the Ignition surge to

individual spark plugs.

Spark plug Creates the

spark due to ionisation of gap

Working Ignition switch is turned on, the current starts flowing through

primary circuit. This current sets up a magnetic field around the soft iron core of the ignition coil.

When the breaker points opens, the current which was flowing through the contact breaker starts flowing through the condenser

As the condenser charges, the primary current falls and the magnetic field collapses.

This change in the magnetic field induces a current in the primary winding which flows in the same direction as the primary current and changes the condenser to a voltage much higher than battery voltage thus stooping the current flow from the battery.

Due to this, the condenser then discharges into the battery, thus

reversing the direction of both primary current and magnetic

field.

This rapid collapse and reversal of the magnetic field induces a

very high voltage in the secondary winding of the ignition coil.

This high voltage is then carried through the high tension

wires to the distributor rotor, where it passes through one of

the ignition harnesses into the spark plug and produces a spark.

CONTINUED..

Advantages Moving parts are absent-so no maintenance. Contact breaker points are absent-so no arcing. Spark plug life increases by 50% and they can be used for about

60000 km without any problem. Better combustion in combustion chamber, about 90-95% of air fuel

mixture is burnt compared with 70-75% with conventional ignition system.

More power output. More fuel efficiency

Disadvantages Because of arcing, pitting of contact breaker point and which will

lead to regular maintenance problems.

Poor starting: After few thousands of kilometres of running, the

timing becomes inaccurate, which results into poor starting (Starting

trouble).

At very high engine speed, performance is poor because of inertia

effects of the moving parts in the system

Sometimes it is not possible to produce spark properly in fouled

spark Ignition Systems plugs.

Application

It is used in all S.I. engines used in modern vehicles.

It is used in engines in industries which requires sparking for

combustion.

Conclusion

Ignition system is very important component of a vehicle.

It harnesses the energy of collapsing magnetic field.

Condenser is used to create voltage much higher tan the

battery voltage.

ANY QUESTIONS?