Ignition system review Chapter 25 and
26 well answered
Function of a ballast resistor - correct answer ✔✔ Reduces current to protect the coil primary
and points
Allows current to increase as speed increases
What are 2 basic ignition system designs? - correct answer ✔✔ Distributor-less ignition systems
Direct ignition systems (DIS)
DIS is commonly used in todays engines
Distributor-less ignition systems are capable of producing much higher energy than the older
distributor ignition system because having multiple coils all for increased current flow and coil
charge time
What components does the primary circuit use? - correct answer ✔✔ Battery
Ignition switch
Ignition coil primary winding
Triggering device
Switching device or control module (igniter)
What are some spark plug made of? (electrode) - correct answer ✔✔ Nickel
Platinum
Iridium
yttrium
Ruthenium
,What are secondary components? - correct answer ✔✔ Ignition coil secondary winding
High voltage cables
Spark plugs
What is the purpose of the primary circuit operation? - correct answer ✔✔
What is the purpose of the secondary circuit operation - correct answer ✔✔ Carries high
voltage to the spark plug, so that the voltage can jump across the gap to complete the circuit so
current can flow
Define knock sensor - correct answer ✔✔ Piezo crystal - produces ac voltage when vibrated or
pressured
May ride on top of a DC voltage
Sends a signal to the ignition control module or PCM to retard timing.
What is EI system? - correct answer ✔✔ Electronic ignition system has spark distribution is
controlled by an electronic control unit and/or the vehicle computer
They run ignition coils for each individual cylinder, some cylinder may share one coil
In EI systems what happens to additional energy that is not released in the form of voltage? -
correct answer ✔✔ It will be released in the form of current flow. This results in higher firing
current and longer spark plugs firing times
What is the purpose of an ignition coil? - correct answer ✔✔ To multiply battery voltage to
force a spark across the air gap on the spark plug.
The ignition coil is a pulse transformer that transform battery voltage into short bursts of high
voltage
True or false:
, If the strength of the magnetic field is doubled, the voltage output doubles - correct answer ✔✔
True
The more loops of wire in the coil, the greater the total voltage induced.
True or false:
Primary wire coils are composed of 100-200 turns and Secondary wire coil consist of 15 000 - 25
000 turns of wire. - correct answer ✔✔ True
Define dwell - correct answer ✔✔ Dwell is the period of time during which there is primary
current flow
Current flows in the primary winding for sometime between firings of the spark plug before it
fully magnetized (saturated)
What is reactance? (in current flow) - correct answer ✔✔ As the magnetic field begins to form
as the current begins to flow, the magnetic lines of force of one part of the winding pass over
another part of the OPPOSITION to current flow.
Reactance causes temporary resistance to current flow and delays the flow of current from
reaching its maximum value.
When maximum current flow is present in a winding, the winding is said to be saturated, and
the strength of its magnetic field will also be at a maximum
True or false:
A typical coil requires 2-6 ms to become saturated - correct answer ✔✔ True
True or false:
Older vehicles that were equipped with ignition coil, it contained oil filled metal housing to help
cool the windings - correct answer ✔✔ True
26 well answered
Function of a ballast resistor - correct answer ✔✔ Reduces current to protect the coil primary
and points
Allows current to increase as speed increases
What are 2 basic ignition system designs? - correct answer ✔✔ Distributor-less ignition systems
Direct ignition systems (DIS)
DIS is commonly used in todays engines
Distributor-less ignition systems are capable of producing much higher energy than the older
distributor ignition system because having multiple coils all for increased current flow and coil
charge time
What components does the primary circuit use? - correct answer ✔✔ Battery
Ignition switch
Ignition coil primary winding
Triggering device
Switching device or control module (igniter)
What are some spark plug made of? (electrode) - correct answer ✔✔ Nickel
Platinum
Iridium
yttrium
Ruthenium
,What are secondary components? - correct answer ✔✔ Ignition coil secondary winding
High voltage cables
Spark plugs
What is the purpose of the primary circuit operation? - correct answer ✔✔
What is the purpose of the secondary circuit operation - correct answer ✔✔ Carries high
voltage to the spark plug, so that the voltage can jump across the gap to complete the circuit so
current can flow
Define knock sensor - correct answer ✔✔ Piezo crystal - produces ac voltage when vibrated or
pressured
May ride on top of a DC voltage
Sends a signal to the ignition control module or PCM to retard timing.
What is EI system? - correct answer ✔✔ Electronic ignition system has spark distribution is
controlled by an electronic control unit and/or the vehicle computer
They run ignition coils for each individual cylinder, some cylinder may share one coil
In EI systems what happens to additional energy that is not released in the form of voltage? -
correct answer ✔✔ It will be released in the form of current flow. This results in higher firing
current and longer spark plugs firing times
What is the purpose of an ignition coil? - correct answer ✔✔ To multiply battery voltage to
force a spark across the air gap on the spark plug.
The ignition coil is a pulse transformer that transform battery voltage into short bursts of high
voltage
True or false:
, If the strength of the magnetic field is doubled, the voltage output doubles - correct answer ✔✔
True
The more loops of wire in the coil, the greater the total voltage induced.
True or false:
Primary wire coils are composed of 100-200 turns and Secondary wire coil consist of 15 000 - 25
000 turns of wire. - correct answer ✔✔ True
Define dwell - correct answer ✔✔ Dwell is the period of time during which there is primary
current flow
Current flows in the primary winding for sometime between firings of the spark plug before it
fully magnetized (saturated)
What is reactance? (in current flow) - correct answer ✔✔ As the magnetic field begins to form
as the current begins to flow, the magnetic lines of force of one part of the winding pass over
another part of the OPPOSITION to current flow.
Reactance causes temporary resistance to current flow and delays the flow of current from
reaching its maximum value.
When maximum current flow is present in a winding, the winding is said to be saturated, and
the strength of its magnetic field will also be at a maximum
True or false:
A typical coil requires 2-6 ms to become saturated - correct answer ✔✔ True
True or false:
Older vehicles that were equipped with ignition coil, it contained oil filled metal housing to help
cool the windings - correct answer ✔✔ True
