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5 Advantages of Electronic Ignition System

Electronic ignition system is one type of vehicle ignition system that is widely applied nowdays.

Why the electronic ignition become main option ?

Of course, electronic ignition systems have better performance in overall. It is very necessary in this time where energy-efficient cars are the new choices.

So what are the advantages of an electronic ignition system if it compared to breaker point ignition system?


At least we found 5 advantages of electronic ignition systems compared to conventional ignition systems.

1. Does not overload the engine combustion

The conventional ignition system uses a distributor device to drive the breaker point, and to distribute the secondary coil voltage to each spark plug. This distributor device is connected to the crankshaft engine, so it can be said that conventional ignition systems overload the engine's performance.

While the electronic ignition system does not overload the performance of the engine because it does not use mechanical devices, the electronic ignition system work electrically without power from crankshaft.

Breaker point, has been replaced using a transistor while the distributor is replaced with an ignition coil module. The device does not work mechanically but works electrically so that it does not overload the engine's performance.

This results in higher efficiency.

2. Bigger fire produced by the spark plug

Electronic ignition systems do not use distributors to distribute secondary voltage, but use a single coil where each coil will be connected directly to each spark plug.


It makes the connection shorter and no voltage is wasted as it is on the distributor, so the secondary voltage is used as a whole to ignite the spark plug. That makes the bigger fire on spark plug.

Then what is the effect if the fire on the spark plug is bigger?

Actually, larger fire is also not good for engine performance, but a clearer flame will certainly make combustion easier. In addition, no secondary voltage is wasted so that the input current on the coil can be reduced. So it saves more electricity.

3. No electrical energy is wasted

As I said above, the electronic ignition system is very effective and saves electricity because no voltage is wasted.

Wasted voltage can occur on improper plate connections. just like distributors, if we study about conventional ignition system we know that distributors work by rotating plates that have been exposed to secondary voltage, the plates will stick to each terminal in turn.

Of course there is the potential for wasted voltage if the connection plate with the terminal does not fit.

In addition, at the breaker point there is a spark. Sparks on the breaker point are absorbed by the capacitor, but from the capacitor the electric current that is absorbed is also directly neutralized to the ground so that there is wasted voltage.

By using electronic parts such as transistors, the above mechanism can be replaced with an electronic scheme without any loss-energy.

See also ; 2 Type of Electronic Ignition System and Differences

4. Suitable for high RPM

We know, the higher the engine RPM, the faster the sparking interval. The faster the sparking interval, the faster the induction interval on the coil.

Meanwhile, conventional ignition only has one ignition coil and one breaker point that will work at intervals according to the induction interval on the coil. So, when the RPM is high, the induction of the ignition coil is less than the maximum so that the fire produced is also relatively smaller.

But in electronic ignition, it has at least two ignition coil and has transistor according to the number of spark plugs. So that the induction interval for each ignition coil is not too fast even at high RPMs. it keeps the fire produced stable.

5. Zero maintenance

That means, the electronic ignition system does not require adjusment as in conventional ignition.

We know, conventional ignition systems use breaker points to trigger induction on the coil. In some time, the opening angle of the breaker point will shift because this is one of the moving parts and there is definitely a wear usage. So it needs an adjusment called dwell angle adjusment.

But in electronic ignition, it is not necessary. The reason, there is no moving part in electronic ignition. So it only relies on the quality of electronic component materials.

When one of the electronic components in the ignition is damaged, then repairs will be done. But as long as there is no damage, no treatment is needed.

Two Types Of Electronic Ignition Systems and Differents

Electronic ignition system is an ignition system that does not use a braker point (breakerless ignition).

Instead, there are electronic devices consisting of transistors and resistors. From there the name of the electronic ignition system was taken.

But, the electronic ignition system has some type.

Today we will discuss two types of electronic ignition systems that are widely diplomatic in vehicles.

1. Transistor ignition system

As the name implies, transistorized ignition system is an ignition system that uses transistors to change the breaker point.

We will repeat a little about the breaker point, the breaker point is the mechanism for disconnecting the primary circuit of the ignition coil. Termination of the primary circuit is intended to trigger the induction of the ignition coil.

The breaker point works like a normal switch which if the plate is stretched the primary circuit will be broken and when the plate is tight the primary circuit is re-connected.

The weakness of the breaker point is the wear on the plate. This is because the plate will always be rubbing against the cam. So that in a certain time it will change the angle and reduce the ignition system performance.

Then what about the transistor?

Transistors are electronic components that has a function like electronic switches.

We know that transistors have three legs, a collector, an emitter and a base. The collector is the input of the primary circuit, the emitter is the output of the transistor going to ground while the base is the transistor controller.

The transistor is working if there is current at the base, it will connect the collector and emitter so in this point, the primary voltage will be continue to the ground. While if the current at the base is stopped, then the emitter and the collector will be disconected.

You can see the transistorized ignition system diagram below


Additional components of the transistorized ignition system;

Pick up coil, this component serves to detect ignition timming. It works by flowing an electric wave where in that wave there is a voltage drop, the voltage drop indicates ignition timming.

The advantages of a transistorized system

  • Do not use breaker points so there is no need to adjust the breaker points.
  • Ignition timing is more accurate
  • Have a simpler scheme

However, transistorized ignition systems still use distributors to distribute high-voltage electricity from the secondary ignition coil to each spark plugs. So it still has mechanical components, therefore it is also called the semi electronic ignition system.

2. Distributorless ignition system

Distributorless ignition system is an ignition system that does not use a distributor. Distributors are required to distribute the high voltage from the secondary output ignition coil circuit.

This component works mechanically, so there is a usage limit where when the limit is reached then the connection to the distributor will weaken so that the spark plug fire weakens.

But on the DLI system, we did not find a distributor. That's because the DLI system already has a full electronic computerized ignition system.

That means, in addition to being full electronic the DLI system has also implemented computer-based calculations as a controller.

In a simple DLI system scheme you can see in the diagram below;

You can see for yourself there are many circuits on the DLI system. It has three main parts, they are ECU, Ignition coil module, and ignition coil pack

ECU is a microcontroller device that functions to regulate the performance of the ignition coil, especially when the ignition coil is active. In doing its job, the ECU is assisted by many sensors such as the crankshaft position sensor to detect ignition timing and camshaft position sensors to detect ignition timming on cylinder 1.

The sensor will send data to the ECU, then the ECU processes the data and the results are sent to the output device, the Ignition coil module.

Ignition coil module actually consists of several transistors, the function is the same as a transistor ignition system that is as an electronic switch. However, this has more numbers. The number of transistors in the ignition coil module matches the number of coil.

Ignition coil pack, is a feature of the DLI system. Coil pack consists of several mini coil. Generally there are two coil (dual coil pack) and four coil (single coil pack).

For dual coil packs, a coil is used for two spark plugs. This causes two spark plugs ignite at the same time, while in a single coil pack one coil is used for one spark plug so that all spark plugs will ignite alternately.

Advantages of DLI systems

  • No maintenance at all because it is full electronic
  • Transfer voltage from the coil is more effective
  • Ignition timing is more accurate


While the disadvantages, DLI systems have quite complicated circuits. For the technicians who hasn't the knowledge will difficult to solve the problem on DLI system. Usually, the error can be detected using a a scanner so that it is more inconvenient and expensive when damage occurs.

Transistorized Ignition System Working and Diagram

Transistorized ignition system is an ignition scheme that reduces the use of mechanical devices, the purpose of transistorized ignition system is to improve the efficiency of the ignition system performance by replacing moving parts such as breaker points.

The main principle of transistorized ignition systems is to use transistors as electronic switches instead of breaker points.

For those of you who already know about vehicle ignition systems, you should know the breaker point or platinum.

Breaker point is a device used to break the primary coil current in the ignition coil so that electromagnetic induction can occur. This breaker point works mechanically by utilizing a cam that can stretch the breaker point gap.

However, the use of breaker points is considered to be less effective, it is because the rubbing components will erode so that it can affect the overall ignition system performance. In addition, when the breaker point is stretched, frequent sparking occurs at the breaker point so that the induction power of the ignition coil is reduced.

That's why there is breaker point gap adjustment.

By utilizing transistors the two things above can be overcome. So we don't need to set the gap.

Why are transistors used instead of breaker points?

As we said at the beginning, the transistor has a function as an electronic switch. There are three legs on the transistor namely base, collector, and emitter.

Collector is input, while emitter is output. The base as a controller, if there is an electric current (low voltage) flows at the base then the current at the input (collector) will flow to the output (emitter).

However, when the electric current at the base stops, the collector is cut off again with an emitter.

So in conclusion, the transistor can be used in the ignition system because of its characteristics that can disconnect and connect lines quickly.

To control the performance of the transistor, we need one additional sensor, the pick up coil. This sensor will send a low-voltage current with pauses according to the ignition timming at the base foot. So that the transistor performance will be matched with the engine RPM.

How does the coil pick up work?

Pick up coil consists of three parts, namely rotor with cam, permanent magnet and coil.


The three components are placed as shown, it is confirmed that the permanent magnet emits a magnetic field that hits the rotor. While the rotor is made of metal which is able to be attracted by magnets.

Cam on the rotor serves to shorten the gap between the rotor with a permanent magnet.

This changing gap causes the current in the pickup coil to be zig-zag. When the cam is parallel to the permanent magnet there is an electric current, but when the cam shifts the current disappears. This drop voltage is used as timming to break the primary current in the ignition coil.

Transistorized Ignition System diagram



  • Battery
  • Ignition switch
  • Ignition coil input
  • Primary coil output
  • Secondary coil output
  • Transistor
  • Pick up coil
  • distributor
  • Spark plug


Transisorized ignition system working procedure

When the engine is started, the crankshaft will rotate the pick up coil so that the pick up coil generates a low voltage current. This will cause the transistor base to be active so that the collector is connected to the emitter.

In the ignition coil, the current from the battery will flow in both coil in the ignition coil.

As explained above, the pickup coil will generate zig-zag electric current. Current from the pick up coil is then transmitted to the base leg of the transistor.

Induction in the ignition coil occurs when the base foot does not get an electric current, but it lasts for an instant, therefore in one cycle of the 4 cylinder engine can occur four times the induction process.

The induction produces high voltage which is distributed to the distributor to be distributed to each spark plug according to the firing order.

Motorcycle CDI Ignition System Parts and Functions

CDI system is one type of ignition system that is widely applied to motorcycles. The CDI system uses the discharged voltage from the capacitor to induce an ignition coil.

As discussed before (CDI system working principle), the CDI system is very different from conventional ignition systems such as battery ignition or magneto ignition.

Then what are the components of the CDI system? let's discuss.

6 Parts of CDI Ignition system and function


Why only 6? that's because the design of the CDI system is simpler so it doesn't need a lot of parts.

1. Source of energy (altenator or battery)

The first component is the energy provider, there are two types of components that can be used as energy providers in the CDI system, alternator and battery.

The alternator can generate electrical energy when the engine crankshaft rotates, the electric current generated is AC. While the battery, is a component of storing electrical energy. The battery can deliver electrical energy directly without turn the engine crankshaft. The electric current generated is DC.

From the explanation above we can see that there is a striking difference between the alternator and battery, the alternator produces AC current while the battery produces DC current. That is why there are two types of schemes in the CDI system, namely the AC CDI system (using an alternator) and the DC CDI system (using batteries).

Although the types of currents are different, both types have the same process. In an AC CDI system, the AC current will be converted into DC by a diode in the CDI unit.

2. CDI unit

CDI unit is a unit that contains several electronic components to trigger the induction of the ignition coil.

So, in this system CDI unit has the same function as breaker point on conventional ignition system.

What are the components in a CDI unit?

  • Diode (AC CDI system)
  • Voltage amplifier (DC CDI system)
  • Capacitor
  • SCR


Diodes are electronic components that have function to convert AC current into DC. As explain in the first point, in the AC CDI system the source of electricity is obtained from the alternator. But the alternator produces AC current.

Therefore, the diode acts as a hardware to convert AC current into DC.

While the voltage amplifier is a special component in the DC CDI system which has function to increase the battery voltage from 12 V to 200 V. This is because the capacitor requires around 200 V voltage for charging while the battery voltage is only 12 V.

But why does the AC CDI system not have a voltage amplifier?

The answer, because the voltage generated by the alternator has reached 200 V so it does not require a voltage amplifier.

Capacitor is an electronic component that can store a voltage at a certain capacity and can release the stored voltage simultaneously. In CDI systems, the discharged voltage of the capacitor is used to induce an ignition coil.

We know before that the capacitor has been charged by the electricity provider (alternator / battery) with a voltage of around 200 V. The voltage will be released simultaneously to cause a very large induction.

While the SCR (silicon controlled rectifier) ​​is a component to determine when the capacitor charged and when the capacitor discharged.

The works of SCR is by open the gate from the power source channel directly to the ground. That will make the current from the power source flow directly to ground so that the capacitor can release voltage.

3. Pick up the coil

The pickup coil is a detector to detect ignition timming. The pickup coil consists of a coil placed near the crankshaft. On the crankshaft there is a protrusion that will hit the pickup coil, this protrusion indicates ignition timing.

When the pickup coil hits the cam, the pickup coil will send pulses or electric waves.

The pulse is sent to the SCR to determine the capacitor. So the pulse from the pick up coil becomes the guidance of the SCR to be active.

4. Ignition coil

The ignition coil on the CDI system works when there is a voltage being applied, this is different from a conventional ignition system that utilizes a drop voltage to induce an ignition coil.

So the ignition coil design is slightly different.

In general the ignition coil on the CDI system is the same as the step up transformer, where the secondary primary has a coil of 100 times more than the primary coil. This causes the secondary voltage to be 100 times greater than the primary voltage, so that when the discharged voltage from capacitor is aplied, then the voltage produced by the ignition coil reaches 20,000 V.

5. Ignition switch

Ignition switch is a device to activate and deactivate the CDI system as a whole. Ignition switches are usually controlled by an ID key, each vehicle has a different key channel.

6. Spark plug

The function of the spark plug is to convert 20,000 V electrical energy into an electric spark. the way the spark plug works is actually quite simple, just by providing a gap between the electrode (+) and ground (-).

Automatically, an electric spark will be formed because the voltage of 20,000 V is very large and is able to jump electrons.

How CDI Ignition System Works On Motorcycle? Check This Out

In the previous article we have discussed the magneto ignition system, where this system is used on small gasoline engines such as on motorcycles.

In addition, there is an ignition system on the motorcycle that is more effective than magneto.

That is CDI (capacitor discharge ignition).

Then what is CDI? How does it work ? and what's the difference with the magneto ignition system? let's discuss together.

CDI Ignition System Definition


CDI consists of two main words, namely capacitor and discharge.

So, the CDI system can be interpreted as an ignition system that utilizes discharging current on the capacitor component.

What is capacitor?

Capacitor is an electronic component that can store electric current, and can release (discharge) the stored current spontaneously.

In conventional ignition systems such as magneto or battery ignition systems, the use of capacitors is only to prevent sparking at the breaker point. But on CDI systems, capacitors have a major role.

The release of current on the capacitor serves to induce the ignition coil.

This is the first difference between conventional ignition systems and CDI. In conventional ignition systems, induction of the coil occurs when the primary current is cut off. But on CDI, induction actually occurs by releasing more current to the primary coil coil.

Please note, the discharge current of this capacitor can reach 400 volts so that the output voltage can still be increased up to 20,000 V by an ordinary step up transformer induction.

For more details, see the diagram below


Components marked above
  • Alternator, as a source of electric current
  • Ignition switch
  • CDI Unit, in which there are several components such as capacitors, series of diodes, SCR (silicon controlled rectifier)
  • Pick up coil, to find out ignition timming
  • Step up / ignition coil transformer, used to increase the secondary voltage up to 20 KV.
  • Spark plug


The alternator used in the CDI ignition system can produce AC voltages between 100 - 400 V. This current is used as the basis for the induction process.

Then how is the process going?

1. Electricity generation on the alternator

Starting when the engine crankshaft is rotated, the energy to rotate the crankshaft get from mechanical energy (kick start) or electric (motor starter).

Previously, in the alternator there were two main components, namely the rotor magnet connected to the crankshaft and the stator coil located around the magnet.

Crankshaft rotation will rotate the rotor magnet on the alternator, the result is the stator coil produces AC voltage. The voltage produced by this alternator ranges from 100 V (low RPM) to 400 V (high RPM). This electricity is then used as an energy source for the ignition system.

2. The process of charging the capacitor

In this process, electric voltage from the alternator is flowed into the CDI unit, inside the CDI unit there are several parts such as;

  • Diode, serves to change the AC current into DC
  • Capacitor, as a storage and electric discharge
  • SCR


The voltage from the alternator will be directly sent to the capacitor, but because the current is still in the form of AC (alternate current), it needs to be changed to DC (direct current).

Therefore, before the current enters the capacitor, it will pass through the diode.

After passing the diode, the current is change from AC to DC and is directly used to charge the capacitor.

3. The discharging capacitor process

The capacitor can release a voltage that was previously stored, if there is no current source that hits it.

Therefore, to make the capacitor discharge its voltage, the primary voltage circuit of the capacitor must be disconnected or at least prevent the voltage from passing through the capacitor.

But how ?

For this matter, we are not talking about breaker points anymore, in the CDI system it is strongly influenced by two components namely the pick up coil and the SCR (silicon controlled rectifier).

Pick up coil is a coil that will conduct electric waves when there is a magnetic field passed it. That means, the pickup coil must be equipped with a magnet as a triger. The pickup coil is mounted near the rotor magnet, while a small magnet is connected to the crankshaft where the angle adjusted to the engine's timming.

When the crankshat rotates, this small magnet will rotate and each rotation this magnet will induce pick up coil oncel. When this process occurs, the pickup coil will generate electrical waves which are sent to input 2 on the CDI unit.

Then the electrical wave from the pickup coil is sent to the SCR. The function of the SCR is to activate the path from the alternator directly to ground.

For this SCR to work, a triger is needed. This triger is provided by the coil pick up. When an electric wave from the pickup coil enters the SCR, it will ignite the SCR to active.

As a result, the voltage from the alternator will directly flow to the ground because the nature of the electric current is always flowing to the ground with the smallest resistance.

When the voltage flows to ground, there is no more supply to fill the capactitor and this makes the capacitor also release its voltage.

4. Induction process on ignition coil

In the circuit above, it appears that the capacitor is connected to the primary coil. When the capacitor releases the voltage, there will be massive voltage flow to the primary coil suddenly, the voltage can reach 400 V.

Through induction on the ignition coil, a primary voltage of 400 V can change to 20 KV on the secondary coil. Then the voltage from the secondary coil is connected to the spark plug.

Induction on the ignition coil will occur for a moment because all voltage in the capacitor will be released at one time. That is why, spark on the spark plug is also only for a moment.

To do the induction in the next cycle, the capacitor need to charge back. It do by turned off the SCR so that the voltage from the alternator can flow back to the capacitor and chagrge it.

The SCR will be active and periodically inactive according to the triger of the pickup coil.

As explained above, the SCR will work when there is an electric wave coming from the pick-up coil while the pick-up coil will generate electric waves when a small magnet passes through the pick-up coil. When the magnet is pulled away it will automatically eliminate electric waves and the SCR is deactivated.

How Does Magneto Ignition System Works? Check Article Below

In the previous article, we discussed anything about the battery ignition system, but there is another ignition system that is almost similar. Magneto ignition system, then what is a magneto ignition system? How does it work ?

In general, the battery and magneto ignition systems are the same as conventional because they still use a mechanical breaker point to induce the coil.

But the difference is located in the source of energy.

We know that the battery ignition system has an energy source from the battery, but what about small engines that don't have batteries? Where does the energy source come from for the ignition system?
chain saw use a magneto system

Then the magneto ignition system is the solution, the magneto ignition system does not require an energy source such as a battery because the power source will be generated by the engine itself.

A mini generator is connected to the engine crankshaft, it will produce electricity when the crankshaft rotates.

The excess does not require a battery, so the engine design can be very light, but for performance it is clearly less than a battery ignition system that has a stable voltage.

Therefore, magneto is widely applied to small gas engines such as chain saws, tractors, air pumps, ATVs, speed boats, motor cylcle.

Then How Does the Magneto Ignition System Work?

As always, we first discuss the components.

  • Magneto unit
  • Ignition switch
  • Breaker point
  • Capacitors
  • Spark plug


The most influence part is the magneto unit, this component not only as a provider of electric current but also has functions as an ignition coil, so naturally in this system we do not see ignition coil components such as the battery ignition system.

Magneto is basically a mini generator, which is there is a permanent series of magnets connected to a crankshaft and two coils around the magnets.

How magneto works is also the same as generators in general, when the permanent magnet rotates there will be intersection of the magnetic force lines so as to produce an electric current in the coil around the magnet.

However, there are two coils inside the magneto, namely the primary coil and the secondary coil. The secondary coil has 20,000 turns and is connected to the spark plug while the primary coil has 200 turns and is connected to the breaker point circuit.

The operational order is the magneto ignition system

1. Start when the engine crankshaft is rotated

The energy to turn the crabkshaft is obtained from an external non-electric source such as a crankshaft rotator or on the motorcycle is a kick starter.

When the crankshaft rotates magneto will produce electricity in both coils with a relatively small voltage.

Meanwhile, the ignition system need extremely high voltage. Therefore, there must be an induction process to produce extremely high voltages.

2. Electromagnetic induction to increase the secondary coil voltage

To increase the voltage to 20,000 V, it is necessary to do an induction process between primary and secondary coil in magneto.

The induction process is also the same as a battery ignition coil where the induction will occur when the magnetic field collapsed from the primary coil into the secondary coil.

To make the magnetic field collapse, the current in the primary coil must be cut off suddenly. In charge of deciding the primary coil current is a series of breaker points.

This circuit consists of a breaker contact and a capacitor.

Breaker contact is a connector from the primary coil to the ground, but this contact can be disconnected by a cam that is also connected to the crankshaft. This means that on certain timings (combustion timming) the cam will hit the breaker point and break the primary coil current.

While the capacitor is in charge of absorbing current from the primary coil when the breaker contact is open.

Capacitor is an electronic component that can absorb the current about it, when the breaker contact is still closed, the current from the primary coil goes directly to the ground but when the breaker contact is open, this current will be absorbed into the capacitor.

The main purpose of the capacitor is actually to prevent the spark on the breaker contact, that is because the gap on the breaker contact is so small that the current from the primary coil is still possible to jump.

What are the advantages of the magneto ignition system?

  • Does not require a battery
  • Light-design
  • Components are simpler and fewer


What is the lack of a battery ignition system?

  • Sparks on small spark plugs when engine RPM is low
  • When the engine RPM is high, the spark on the spark plug is also quite large
  • Need more effort to start the engine

How Does Ignition Coil Works? Let's Discusse

Why does the ignition system have an ignition coil? what is its function and how does it work? We have written all the explanations below.

Ignition coil is one of the main components in the ignition system. The function of the coil is to change the battery voltage from 12 V to 25 KV.

Some people assume that ignition coil is only found in traditional ignition systems such as battery ignition systems or magneto ignition systems.

In fact, ignition coil can also be found on cars manufactured today. However, the igniton coil has changed a lot.

In the past, there was only one tubular coil that worked for all spark plugs. But now, there is a single coil or dual coil pack system where an engine does not only have one coil for all but one coil for each spark plugs.

What is the ignition coil function?

Its function is only to increase the ignition voltage.

Why does the ignition voltage have to be increased?

The reason is that in order to create a fire jump on the spark plug the battery voltage must be increased thousands of times. If the voltage is only 12 V then there will not be a stepping flame on the spark plug electrode, because to make electron jumps in an air gap, a large voltage is needed.

How does the ignition coil work?

To understand the working principle of an igniton coil, you need to study the igniton coil diagram below.


Main Ignition coil component

  • Primary winding
  • Secondary winding
  • Iron core


In general, ignition coil works the same as step up transformer. Step up transformer, using the electromagnetic induction method to increase the input voltage.

The way it works, there are two coils. Primary and secondary coils, primary coils are located inside while  the secondary coils located in outer side, so the magnetic field of the primary coils will hit the secondary coils.

If the number of turns of the secondary coil is less, the output voltage will decrease but if the number of turns of the secondary coil is higher then the output voltage will increase.

That is what happens during induction.

But on ignition coil, there is a little difference. In the ignition coil, the secondary coil is located inside the primary coil as illustrated above.

Then how does induction take place?

It turns out that the induction of the ignition coil does not occur when there is a current that passes through the igniton coil but it occur when the current in the ignition coil is cut off.

Primary coil will issue a magnetic field when electrified, this magnetic field will occur in the outer area due to the position of the primary coil in the outside area. When the electric current is cut off, the magnetic field that was previously formed will move very quickly towards the inside before finally disappearing.

The fast and simultaneous movement of the magnetic field will induce secondary coils with stronger results.

As a result, the secondary voltage has increased hundreds of times from 12 V to around 25 KV.

Then what is the function of the iron core in the ignition coil?

Its function is to pull the magnetic field from the primary coil, so that the movement of the magnetic field described above will be focused in very quickly.

The good conductor like iron, will be very effective to maximize the induction in the coil. Without this iron core, it is possible that the induction results could not reach 25 KV.

Battery Ignition System Parts And Functions (Full Explained)

Battery ignition system or some call the conventional ignition system is one of many type of ignition system that is widely applied to used cars. But now, the ignition system has changed to full electronic.

However, the basis of an electronic ignition system comes from a battery ignition system.

Therefore, as car enthusiasts, we must keep learning how the battery ignition system works because it is the basis.

We have discussed the article about battery ignition system in the following link; Easy to understand, Battery ignition system working principle

In this article, we will focus on discussing the components of the battery ignition system and each function.

Battery ignition system components consist of;

  • Battery
  • Ignition switch
  • Ballast resistor
  • Ignition coil
  • Contact breaker
  • Capacitor
  • Distributor
  • Spark plug
  • High voltage wire


1. Battery

As the name suggests, the battery is a main part of the battery ignition system. The function of the battery in this system, is as a power source.

Basically, sparks on spark plugs occur as a result of electron jumps with very high voltages. so the source of energy, is electrical energy derived from vehicle batteries.

Generally for passenger vehicles (MPV, SUV) use 12 V batteries.

2. Ignition switch

Ignition switch is a part to manually activate or deactivate the ignition system of the vehicle.

Called manually because we control it.

In the past, the ignition switch was still in mechanical form using plate connections. To activate it, we need to enter the vehicle key and turn it to the ON position.

But now, there is a keyless technology where we do not need to enter the vehicle key into the ignition switch.

However, that does not mean the car now does not include ignition switches. Ignition switches remain only in a more electric form.

3. Ballast resistor



Is a resistor with a high resistance level, its function is to regulate the current that flow to the ignition coil.

What is the purpose?

In general, there are two objectives, to launch better starting system, and to avoid hot temperatures of ignition coil.

During the starting process, the starter motor requires a large amount of current to turn the engine crankshaft. At the same time, the ignition system is active. If there is no resistor, more electric current will enter the ignition coil than the starter motor.

Because the ignition coil has smaller load than the starter motor load so naturally the electric current will flow more to the smaller load.

To avoid this, a high resistance resistor is placed to limit the amount of current entering the ignition coil, so that the starter motor can work stronger.

In addition to the starting process, the electric current can also affect the ignition coil temperature. Large currents cause high ignition coil temperatures, while high temperatures can reduce electromagnetic induction.

Therefore, the ballast resistor also serves to maintain the ignition coil temperature so that it is not too hot.

4. Ignition coil

Is a step up transformer which function is to increase the voltage. The working principle of the ignition coil is also the same as a transformer that uses two coils with different number of turns.

But the thing that make it different is, the primary coil is located on the outside while the secondary coil is located on the inside.

Then how does electromagnetic induction take place?

It turns out that induction occurs when the electric current in the primary coil is cut off. The process is like this, when the current in the primary coil is still connected, magnetic fields appear around the primary coil. When the primary coil current is suddenly cut off, the magnetic field moves inside before finally disappearing.

When the magnetic field moves rapidly inside of the secondary coil, that's when electromagnetic induction occurs.

The article about ignition coil will be full explained on this article How does ignition coil works ?.

5. contact breaker / breaker point



It is a mechanism to disconnecting and connecting current on the primary coil quickly and precisely.

In this mechanism there are three main components, namely cam breaker, arm breaker and breaker point.

Contact breakers work mechanically, using two contacts. When these two contacts are connected, the primary coil current is also connected. But when these two contacts are separated, the primary coil current is also separated.

The component for separating contact breakers is cam breakers. Cam breaker consists of cam which can bring up the breaker arm. When the breaker arm is raised, the contact will separated. Conversely, when the cam shifts, the contacts are connected again.

6. Capacitor

Serves to prevent splashes in the contact breaker.

Although it is not a main part, capacitors greatly affect the performance of the ignition system. Because when there is a spark on the contact breaker, the primary current is not cut off so there is no induction in the ignition coil.

In fact, the breaker contact gap is so small that a spark could appear even though it is only 12 V.

To prevent this, the capacitor is located after the breaker point and before the ground. Capacitor is an electronic component that is able to store a little electricity and immediately release it when the current source is stop.

When the contact breaker is still connected, the capacitor will store current, when the breaker contact is broken the capacitor will release an electric current (discharge) so there is no potential difference in the two contacts.

That is why there is no spark.

7. Distributor



Is a component for distributing the ignition coil output (secondary coil) to each spark plug with the appropriate firing order.

You can only find distributors on engine that have more than one cylinder such as a car. While for single cylinder engines such as motorcycle, there are no distributors.

8. Spark plug

Spark plugs are components for converting electrical energy into sparks.

How did it happen?

Spark plug uses the air gap principle that utilizes the potential difference between the electrode (+) and ground (-). So when high-voltage electricity reaches the spark plug electrode, the electron automatically jumps to the ground because the higher the voltage, the higher the potential difference.

The higher the potential difference, the stronger the electron's movement.

Actually the electron jump is not a fire, but just a flash of electricity. but also has a burning effect, so it can be used for combustion.

9. High voltage wire

It is a special cable used to carry 20,000 V electrical energy from the ignition coil to the spark plug.

The diameter of this cable is quite large, sometimes when we touch the cable insulator, we can be electrocuted even though not dangerous. That shows how high the voltage of this spark plug wire.