Parts Of Conventional ignition - What is the function of
ignition system? most of you must have known, that the ignition system plays a
role in combustion triggering through spark plugs. In the process of combustion,
spark plugs can emit sparks because there are super high voltage electrical
curent resulting from ignition coil.
This voltage amount is change, using the principle of
electromagnetic induction such as step-up transformer. The process is occurs because a primary coil have fewer amount of
voltage than secondary coil. When the primary coil voltage disconnected, the is
a movement of magnetic field inside the secondary coil. That’s why the
secondary coil have much bigger voltage.
The ignition system, used to carry out the converting
circuit from a 12 volt electric battery voltage up to 20 KV on the spark plug.
To perform this circuit, the ignition system is supplied by several components
that connected each other. Below is the component of a conventional ignition
system that plays a role in a series of sparking a all spark plug on 4 stroke
engine.
Name of the Conventional Ignition Component and their Functions
1. Battery
Battery has a function for provide a current source, why
does battery include the ignition component? instead of the battery it's the
vehicle's electrical components? indeed and the ignition system of one of the
car's electricity, so all that needs an electric current must include the
battery as its component.
Normal battery voltage, 12 volts either on motorcycle or
car. The difference between the motorcycle and car battery is not the voltage
but the power inside the battery. This is because the electric power in the car
is larger, in addition to ignition systems there are also lighting systems and
accessories that require large electrical power.
2. Key contacts
Some of us recognize the ignition key as a engine-saving
device, or a component to turn on the engine starter. That's right, but it's
not just the function. If you see the ignition hole there are 4 positions
namely;
- Off Position
- Position Acc
- Position On
- ST position
At the Acc position, the ignition system is still not active
in the sense that no current has entered the primary coil. The electricity will
go into the primary coil when we put the ignition key ON position. In this
position, not only the primary coil gets current but the entire vehicle's main
system is also ready to be activated.
3. Ignition coil
This is the most important component, because it carries the
function as a step-up transformer, or raise the battery voltage. As we
mentioned above that this coil works with the principle of electromagnetic
induction using two coils. Where the number of secondary coil coils is more
than the primary coil, so when magnetism of the primary coil go inside the
secondary coil there can be an increase in voltage.
4. Distributor
In conventional ignition systems, the distributor becomes a
component used in determines of timming and Firing order. The distributor
consists of a shaft connected to the cam, the cam is used to disconnect the
flow of the primary coil.
Meanwhile, at the close of distributor you will find two
main components related to the fairing order. Namely the rotor and distributor
cap. The rotor is a conductor component that distributes the output from the
coil to the spark plug according to the FO, while the distributor cap is the
base of the spark plug wire to channel and receive the coil output to the
rotor.
5. Contact point / platinum
Contact point or breaker point is a switch-like regular plate
that can be disconnected and connected. What its function? this is like a coil
working principle where to produce a large output voltage need to do the
primary current termination. This contact is in charge of deciding the primary
current in correspond with the angle of ignition.
The breaker point will disconnect primary curent when the
distributor cam touches the ebonit or foot of breaker point. When the foot is
touched, then the contact will open and cause the primary current is
disconnected. This contact is also familiarly called platinum because it uses
platinum metal at its contact end.
6. Vacuum advancer
Vacuum advancer, served on spark advancing, or changing
ignition timming. Why does timming need to be changed? This aims to adjust the
condition of the engine with ignition, e.g when the engine carries a heavy
load. This condition will cause slow piston movement even if the valve is fully
open.
If timming remains, then it could be a contra effect that
only inhibits the piston rate. To adjust it, the ignition timming will be
reversed almost 0 degrees so that the combustion expansion can be fully
utilized to push the piston down.
Vacuum advancer will reverse the ignition based on the
engine load, it is detected from the vacuum in the intake manifold. If the
condition is as above then the suction power on the piston decreases, and
contact point will shift more slowly.
7. Governoor advancer
Centrifugal governoor advancer is also have same function as
vacuum advancer, governorr advancer function is to change the ignition timming of
engine based on engine RPM. Conditions, if the engine work on high RPM then
ignition timming must be made earlier in order to prevent knocking and self
ignition.
The governoor advancer uses two weight ballast that can
stretch based on the centrifugal force on it. This ballast will be attached to
the distributor shaft and the spindle shaft will give rise to centrifugal force
in the ballast, the weight ballast strain used to accelerate the platinum open
angle.
8. Capacitors
Capacitor or condenser is an electronics component that has
the ability to absorb the current and remove it when necessary. In conventional
ignition, this capability is used to absorb spark in the gap of breaker point
when its disconnected.
When the point contact opens, the primary coil current
should be disconnected. However, the platinum opening is only about 0.5 mm.
With this small gap, there is a possibility electrical jump that causes sparking
on the gap of breaker point and the
interruption process is interrupted.
With the capasitor then when platinum opens, the electric
current will be transferred to the capasitor that has the connection. But the
current is not stored inside the capasitor because it is directly connected to
the ground. This process will make the capasitor immediately experience a
vacuum so that it can be used quickly and repeatedly.
9. Spark Plug Wire
Cable on the spark plugs, have different shapes and
capabilities with common cables. These cables are usually made of
large-diameter copper with a thick insulator. This is because the spark plug
wires will connect the super high voltage from the output secondary coil. So it
takes a cable that has great endurance.
10. Spark plugs
The last component in the ignition system of the gasoline
engine is the spark plug. The spark plug consists of a core or electrode rod as
the receiver of the electric current from the output coil and the ground located
in the body of the spark plug. The gap you see on the spark plug, it's a gap
between the electrode tip that has a positive electric and ground that has
negative electricity.
So if the electric current on the electrode has a large
voltage, then the electricity is able to exit or jump to the ground, that’s form
of sparks. That's how spark plugs produce fire.
So the complete article and super clear about the parts of
conventional car ignition systems and their functions. Hope can increase our
insight and benefit us all.