IGNITION SYSTEMS Prepared By: Aalap Shah (u12me072) Shekhar
Punmia (u12me073) Amit Yadav (u12me074)
TABLE OF CONTENT REQUIREMENTS OF AN IGNITION SYSTEMIGNITION
SYSTEM FUNCTIONTYPES OF IGNITION SYSTEMBASIC IGNITION SYSTEM
COMPONENTSBASIC IGNITION SYSTEM CIRCUITPRIMARY CIRCUIT AND ITS
COMPONENTSECONDARY CIRCUIT AND ITS COMPONENT
REQUIREMENTS GOOD SPARK AT THE CORRECT TIMING.EFFICACY OVER
ENTIRE RANGE OF SPEED.LIGHT ,EFFECTIVE AND RELIABLE.NEGLIGIBLE
INTERFERENCE FROM THE HIGH VOLTAGE SOURCE WITH THE RADIO AND
TELEVISION RECIEVERS INSIDE THE AUTOMOBILE.
IGNITION FUNCTIONProduces 10k to 20k volt spark across spark
plugDistributes high voltage spark to each spark plug in correct
sequenceTimes the spark so it occurs as piston is nearing top dead
centerVaries spark timing with load, speed, and other
conditions
TYPES OF IGNITION SYSTEMBATTERY IGNITION SYSTEMDIFFICULTIES WITH
DISCHARGE.CURRENT OBTAINED FROM BATTERY.GOOD SPARK EVEN AT LOW
SPEED.USED IN CARS AND LIGHT COMMERCIAL VEHICLES. MAGNETO IGNITION
SYSTEMNO BATTERY HENCE NO DISCHARGE.CURRENT GENERATED BY
MAGNETO.QUALITY OF SPARK POOR DUE TO LOW SPEED.USED IN RACING CARS
AND TWO WHELERS
BASIC IGNITION SYSTEM COMPONENTSBATTERYIGNITION SWITCHIGNITION
COILCIRCUIT BREAKER, CONDENSORIGNITION DISTRIBUTORSPARK
PLUGSIGNITION SYSTEM WIRES
BASIC IGNITION SYSTEM CIRCUITBattery supplies power to entire
systemIgnition Switch turns engine on or offCoil transforms
voltsSwitching device triggers ignition coilSpark Plug and wires
distribute spark
PRIMARY CIRCUITConsists of low voltage wiring and componentsUses
conventional type automotive primary wiresControls when ignition
will take place. (When coil fires)
COMPONENT OF PRIMARY CIRCUITBATTERY: Generally 6 Volts or 12
volts lead acid type storage battery is used.SWITCH: To turn engine
on or off.BALLAST COIL: It consist of Iron wire. If the coil is
heated up due to excessive current, the resistence of ballast coil
also increase, thus reducing the current flow, preventing the
damage to primary coil or battery.
COMPONENT OF PRIMARY CIRCUITINDUCTION COIL: Core is made of soft
iron primary coil haveng 100 to 200 turns, While secondary has
10,000 or so.BREAKER POINT: It switch on and switch off the primary
circuit, Opening and closing is achieved by cam rotating at half
the speed of crank shaft for a four stroke engine.CONDENSOR: To
activate secondary circuit in order to produce large emf and also
to protect metal poing by absorbing extra emf.
IGNITION COILTRANSFORMER2 SETS OF WINDINGSPrimary
windingsSecondary windingsIRON COREPRODUCES MAGNETIC FIELD
SECONDARY CIRCUITDistributes current to individual cylinders to
jump spark plug gapMust have thicker, heavier insulation on
wiresTypical voltage to jump gap - 10K Volts
COMPONENT OF SECONDARY CIRCUITDISTRIBUTOR ROTOR: It is located
in upper part of the ignition unit, It has a rotor, and high
tension terminal attached to it.
COMPONENT OF SECONDARY CIRCUITSPARK PLUG: The Spark plg produce
a high tension spark between the electrodes(10k to 20k volts).
