Download Types of Ignition System

Spark Plugs
Chapter 1 Outline
4 Types of Ignition System
Structurally, ignition system can be classified into the
following three types.
Contact Ignition Type
1
Battery
2
Ignition switch
3
Ignition coil
4
Breaker point
5
Distributor
6
Rotor
7
Spark plug
1
Battery
This system generates high voltage by
cutting off the current with transistors in the
igniter. This system can provide stable high
voltage.
2
Ignition switch
3
Coil with an igniter
Demerit
4
Signal generator
The ignition timing is controlled by the signal
generator in the distributor, so there are
limits to fine control.
5
Distributor
6
Rotor
7
Spark plug
(Ordinary Ignition Type)
In this system, the current (primary current)
flowing to the ignition coil from the battery is cut
off at the mechanical contacts (breaker points)
in the distributer to generate high voltage.
Demerit
Since these are mechanical contacts,
sparks can fly between the contacts or the
voltage drops at low speed. Also,
sometimes current does not flow adequately
due to soiling of the contact surface.
Transistor Ignition Type
Electronic Spark Advance (ESA, DLI)
Electronic ignition type
(ESA:Electronic Spark Advance,
DLI:Distributorless Ignition)
The ignition timing and dwell angle are
controlled by microcomputer, which sends
the ignition signals to the igniter, where the
transistors inside the igniter cut off the
current and generate high voltage. This
makes more precise control possible and is
the current mainstream ignition system.
Distributor
IGt
Engine speed .NE
Crankshaft
position detection .G
Ignition timing
control
Sensors
Air flow sensor
Water temperature
sensor Air conditioner
signal etc
Igniter
ECU
Dwell angle
control
Constant-current
control
Ignition
signal
Ignition
Dwell angle
reduction
IGf
Ignition monitor signal
5 Comprehensive Test
From the following statements about ignition system, select the incorrect one.
1 Both gasoline engines and diesel engines require spark plugs to ignite the air-fuel mixture.
2 The ignition timing is adjusted according to changes in the engine speed and load.
3 The air-fuel mixture for gasoline engines is the proportion of air and gasoline by weight and about 15:1 is called the stoichiometric air-fuel ratio.
4 The spark voltage for spark plugs is generated when the primary current through the igniter is cut off.
5 4-cycle engines ignite and combust each cylinder one time for two rotations for the engine crankshaft.
Answer on next page
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