2. What is ignition system???
The system in an internal-combustion engine that produce the spark to
ignite the mixture of fuel and air.
Types of ignition system
Battery ignition system
Magneto ignition system
Electronic ignition system
3. Battery ignition system
• Coil ignition system
• Used in SI engines.
• Main parts are battery, ignition switch, ignition coil, distributor,
breaker point, pivot arm, cam, capacitor, rotor, spark plug, high
tension wiring.
5. Working of Battery Ignition System
• In the battery ignition system ignition coil stores the energy in form of
magnetic field and deliver it at the instant of ignition, in form of high
voltage current with high tension wire to correct spark plug. The diagram
of four cylinder battery ignition system is as follow.
• First low voltage current flow form battery to the primary coil through
ignition switch and ballast resistor.
• Ballast resistor regulates the temperature of ignition coil by regulating
current passing form it.
• The ignition capacitor connected in parallel with contact breaker. One end
of secondary winding is also grounded through contact breaker.
• When the ignition switch is closed, the primary winding of the coil is
connected to the positive terminal, and current flow through it known as
primary current
6. • The current flows form primary coil produces a magnetic field which
induces an EMF in secondary coil.
• The cam regulate the contact breaker. Wherever the breaker open,
current flows into condenser, which charged the condenser.
• As the condenser become charger the primary current falls and the
magnetic field collapses. This will induces a much higher voltage in
condenser.
• Now the condenser discharge into the battery which reverse the
direction of both primary current and magnetic field. This will induce
a very high EMF in secondary winding
• Now this high voltage EMF produce spark at correct spark plug
through distributor.
7. 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.
8. 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
