While the automotive industry has historically made tremendous mechanical and technological advances, all cars with combustible engines have one component in common: the ignition system. What are the types of ignition systems? If you’re serious about your precious vehicle, understanding how different types of ignition systems work and their pros and cons can help you choose the most effective spark plug based on your ignition system’s performance requirements.
Although almost every major component of the car has undergone improvements over the years, the fundamentals of the ignition system have not changed in almost a century. Essentially, it takes a voltage from the battery, converts it to a higher voltage, and then transmits this current to the combustion chamber of the engine and ignites a compressed mixture of fuel and air to produce combustion. This combustion produces the energy needed to run the car.
The ignition system plays a vital role in generating combustion to run your car.
That is, thanks to technological advances, the methods of generating and distributing sparks have been greatly improved. What are the types of ignition systems? Currently, in order of invention, most cars and trucks use four types of ignition systems: conventional breaker (mechanical) ignition, high-energy (electronic) ignition, distributorless (waste spark) ignition, and coil turn-on. Plug ignition. Breakpoint (mechanical) ignition and high-energy (electronic) ignition are both distributor-based ignition, so another classification method is based on three broader types of ignition systems: distributor-based, dispenser-free, and coil-plug systems.
In this comprehensive guide to how automotive ignition systems work, we’ll take a deep dive into how each system works, as well as the resulting pros and cons of each, and what it means for your engine performance and maintenance requirements.
Car Ignition System Tutorial: What Does the Ignition System Do?
When you insert the key into your vehicle’s ignition and turn it, your engine will start and continue running. Have you ever wondered about the whole process that happens behind such a simple action?
Let’s go back to engine 101: your engine generates the power to drive the car by creating combustion or explosion in its combustion chamber, hence the name “internal combustion engine”. To create this combustion, the ignition system plays an important role: your spark plug provides an electrical spark that ignites the air and fuel mixture that enters the combustion chamber.
The spark plug of the ignition system ignites the air-fuel mixture, hence the name “ignition”.
For an ignition system to function properly, it must be able to accomplish both tasks effectively and accurately at the same time.
Create a spark that is strong enough to be hot
The first task is to create a strong spark that can jump over the spark plug gap. In other words, the ignition system needs to increase the voltage from 12 volts to at least 20,000 volts of the battery, which is necessary to ignite the compressed air and fuel mixture in the combustion chamber to produce energy to produce an explosion.
In order to achieve such a huge voltage surge, the ignition system of all automobiles, except for diesel-powered models, uses an ignition coil consisting of two coils wound around the core, called the primary and secondary windings. The ignition coil acts as a power transformer.
The goal of the ignition coil is to create an electromagnet by passing the 12 volts provided by the battery through the primary windings. When the ignition system of the vehicle triggers a switch to turn off the power to the ignition coil, the magnetic field collapses. In doing so, the secondary winding captures the collapsing magnetic field from the primary winding and converts it to 15,000 to 25,000 volts.
It then supplies this voltage to the spark plug, which creates combustion in the combustion chamber of the engine, which generates the energy to start and run the vehicle’s engine. In order to generate the necessary spark, the conversion voltage transmitted to the spark plug must be in the range of 20,000 to 50,000 volts.
Light the spark at the right time
At the same time, another important role of the ignition system is to ensure that the spark must be ignited at just the right moment in the compression stroke to maximize the power generated by the ignited air and fuel mixture. In other words, enough voltage must be delivered to the correct cylinder at the precise time, and it must be done often.
All components work precisely and harmoniously to get the best performance out of your engine. Even the slightest timing error in any single part can lead to engine performance issues and can even cause permanent damage if the time is extended.
The ignition system must provide enough spark on the correct cylinders. To ensure accurate ignition timing, engineers use a variety of methods that have evolved over the years.
Early ignition systems used a fully mechanical distributor to control ignition timing, followed by a hybrid distributor equipped with a solid-state switch and an engine control module (ECM), essentially a computer with simple processing that distributed power to each individual cylinder.
Later to overcome the shortcomings of these early dispensers were 100% electronic ignition systems, the first of which was a dispenser-less ignition system, and the dispensers were completely eliminated.
The latest invention, the coil-to-plug ignition system, is able to significantly improve spark timing by using an improved ignition coil that has a greater impact and produces a hotter spark.
A guide to how an automotive ignition system works: What each component of an ignition system does
Components of a conventional ignition system.
battery
When the engine is running, it also runs an alternator, which generates electrical energy to charge the battery. The battery in the car stores electrical energy and dissipates it as direct current.
The battery provides 12 volts of direct current. However, in order to achieve a burning spark, the spark plug needs to have a voltage of 20,000 to 50,000 volts. To achieve such a significant increase in voltage, you need an ignition coil.
Ignition coil
The ignition coil converts the low voltage from the battery into the high voltage required by the spark plug
The ignition coil acts as a power transformer. The earliest mechanical ignition systems relied on a coil to convert the low voltage from the battery into the high voltage required by the spark plug.
The electrical conversion of the ignition coil works according to a principle called magnetic induction. In a conventional transformer, the primary coil receives electricity, i.e., direct current from the battery. However, this charge through the primary coil is periodically interrupted. This interruption was caused by the dispenser in the earlier dispenser-based ignition system, as well as by the computer when it achieved more precise determination in the later ignition system. The work of distributors is discussed further below.
The voltage in the primary coil creates a magnetic field. The periodic interruption of the current received by the primary coil causes the magnetic field generated by the primary coil to constantly collapse. Such a large movement of the magnetic field of the primary coil causes the secondary coil to generate high-voltage energy one at a time.
How high the voltage generated by the secondary coil depends on the ratio of the number of turns of the primary coil to the number of turns of the secondary coil. If the secondary coil has twice the number of turns than the primary coil, the output voltage will be twice the input voltage. So, to increase the voltage from 12 volts to the minimum of 20,000 volts required for a spark plug, in the ignition coil of a car, the secondary coil has tens of thousands of turns as the primary coil.
Distributor
Here’s how the splitter creates the above periodic discrete charges supplied to the primary ignition coil. The splitter contains a “circuit breaker point” that connects the primary coil circuit to ground. The point is connected to the ground by a lever. The lever is moved by a cam connected to the distributor shaft. This opens up the primary coil circuit and causes a crash, triggering a burst of high voltage in the secondary coil.
In addition, while the battery and ignition coil provide power, the distributor performs an important job of precisely determining when and where the power supply reaches each spark plug.
The distributor precisely determines where and when the power reaches each spark plug.
The distributor contains many components, the most important of which include a rotor that rotates synchronously with the engine, and multiple “contacts” mounted on the distributor cover. The current from the ignition coil is supplied to the rotor. The rotor rotates, and when the end of the rotor approaches one of the contacts, the contact generates an electric arc. From there, electricity is transmitted along the spark plug wire to the relevant spark plugs, which time each spark plug.
Car ignition system tutorial: spark plugs and their wires
A spark plug wire, also known as an ignition wire, is an insulated wire that carries electricity to the spark plug so that the spark plug can eventually produce a spark that causes combustion.
The spark plug consists of an insulated ceramic body with a conductive metal center core in the center. There is a gap between this metal center core and the tip of the electrode that is grounded to the metal base of the spark plug. arcing or skipping that gap, resulting in a spark.
How important is the ignition system
The conclusion is that if the ignition system is not working correctly and accurately, your car may not start or not operate at all.
Worn spark plugs and faulty parts in the ignition system can affect your engine performance, causing a variety of engine problems, including difficult starting, misfires, lack of power, poor fuel economy, and even permanent damage if not addressed in time. Also note that these engine issues caused by ignition system failure can damage other critical components in the vehicle.
Therefore, regular maintenance of the ignition system is essential to ensure optimal engine performance as well as a smooth and safe ride. So how is regularity sufficient? At least once a year, you must perform a visual inspection of your ignition system components to check for signs of wear or failure, and then replace them immediately if needed.
When it comes to your spark plugs, be sure to inspect and replace them at the intervals recommended by the vehicle manufacturer. Similarly, given the importance of ignition systems, preventative maintenance is key to maximizing engine performance and life.
4 Types of Ignition Systems: #1 Distributor-Based Circuit Breaker Ignition (Mechanical)
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What are the types of ignition systems? The oldest type of ignition system is the traditional break-point ignition system, sometimes referred to as a mechanical ignition system. It has been used since the early days of the automotive industry, especially in the 1970s.
It is one of two types of ignition systems that use a dispenser, known as a dispenser-based system. Unlike the other three types of ignition systems discussed further below, circuit breaker ignition systems are completely mechanical in nature, hence the name.
Let’s understand how they work, and then on this basis we will see the advantages and disadvantages of this type of ignition system. We’ll delve into more details in this section, as the mechanical circuit breaker point system was the earliest invention and therefore the basis for all later models. You should have a solid understanding of how this system works and look at the pros and cons of the system that was improved later.
A brief description of dispenser-based ignition
In contrast to the other two distributorless systems, the first two types of ignition systems, i.e., the circuit break point system and the electronic system, are based on distributors. So, let’s understand the basics of how a distributor-based system works.
The distributor is a closed rotating shaft with mechanically timed ignition. The main job of the distributor is to transfer the secondary or high-voltage current from the ignition coil to the spark plug in the correct ignition sequence and at the right time.
In a fully mechanical distributor, the distributor is connected to a camshaft with a gear and gets rotated by the camshaft. Internally, a polygonal cam on the distributor shaft moves other distributor parts, essentially like a mechanical switch that starts and stops the power flow to the ignition coil.
Once the coil has generated enough voltage, it reaches the top of the coil and goes to the top of the distributor cover. There, a rotating disc connected to the distributor shaft distributes the current sequentially to each spark plug wire. The current travels down the spark plug wire to the spark plug and causes ignition.
Guide to the working principle of the automotive ignition system: The working principle of breakpoint ignition
The distributor-based circuit breaker ignition system has two circuits, a primary circuit and a secondary circuit.
Wiring diagram of a distributor-based circuit breaker ignition system.
An ignition coil consists of two coils wound around an iron core, called a primary winding or primary coil, a secondary winding or a secondary coil. The primary circuit consists of a primary coil, a “circuit breaker point”, and a car battery. It only operates at the low current of the battery and is controlled by a circuit breaker point and ignition switch.
At the same time, the secondary circuit consists of a secondary winding in the coil, a high-voltage lead-out coil wire on the external coil distributor, a spark plug, a spark plug lead, a distributor rotor, and a distributor cover.
When the ignition key is opened, the primary coil receives a low-voltage direct current from the battery, which is returned to the battery through the circuit breaker point of the power distributor. This current creates a magnetic field around the ignition coil.
Now here’s how “breakpoints” come into play.
As mentioned above, the splitter contains a “break point” that connects the primary coil circuit to ground. This breaker point is connected to the ground by a lever that is moved by a cam connected to the distributor shaft.
Since the distributor rotor rotates synchronously with the engine, when the engine rotates, the distributor shaft cam rotates until the high point on the cam causes the circuit breaker point to separate. In an instant, this abrupt separation stopped the current flowing through the primary coil.
The cam lobes push the spring-loaded arm attached to the breaker point; This opens and closes with the rotation of the engine at the time point.
This causes the magnetic field generated by the primary coil to collapse around the coil. The capacitor absorbs energy and prevents the circuit breaker points from arcing between them every time they separate. So in other words, the capacitor acts in the rapid collapse of the magnetic field, which is necessary to create a high-voltage surge in the secondary coil.
This abrupt and continuous change in the magnetic field of the primary coil can pass through the secondary coil, creating a high-voltage surge high enough to skip the gap between the rotor and distributor cap terminals and the gap between the spark plug electrodes. Assuming that the entire system is properly timed, the spark reaches the air-fuel mixture in the specified cylinder at the exact moment, and combustion takes place in that cylinder.
As the distributor continues to rotate synchronously with the engine, the electrical contact between the rotor and distributor cap terminals is interrupted, preventing the current from flowing to the secondary coil. At the same time, the circuit breaker point closes again, leaving the primary circuit intact and allowing current to flow through the primary coil again.
This current will again create a magnetic field around the primary coil, which will collapse again, and the cycle will be repeated for the next cylinder in the ignition sequence. It should be noted that in the circuit breaker point system and later in the electronic system, a single coil consisting of primary and secondary windings supplied power to all cylinders.
The entire “magnetic induction” process occurs about 18,000 times per minute at a speed of 90 miles per hour.
Summary of breakpoint ignition:
merit
- Ease of maintenance: The mechanical characteristics of these ignition systems, as well as the fact that these systems have been in use for the longest time, make them relatively easy to diagnose and repair.
shortcoming
- Breakdowns can occur: However, they are made up of a large number of mechanical moving parts, thus also increasing the likelihood of wear, malfunctions, and failures.
- Affect engine performance: This possible deterioration of these types of ignition systems can reduce the maximum spark energy over time, leading to frequent engine problems such as misfires and increased emissions.
4 Types of Ignition Systems: #2 Dispenser-based electronic ignition
history
Electronic ignition system kit.
More than 70 years after the advent of fully mechanical breakpoint ignition systems, the automotive industry is faced with the need for higher mileage, higher reliability, and lower emissions. The manufacturer has proposed a high-energy ignition system that relies less on mechanical work: the electronic ignition system.
Circuit breaker points in early systems would fail and disrupt ignition timing, negatively impacting engine performance and requiring replacement every 12,000 miles.
To address this shortcoming, later electronic ignition systems still had a distributor, but the circuit breaker points and capacitors had been replaced with a pickup coil that acted as a transistor switch, and an electronic control module that controlled the ignition coil to generate high voltages. – Voltage and current.
Using this electronic switch to control timing means fewer moving parts than earlier open ignition systems, making these electronic ignition systems relatively easy to diagnose and service. They also improve the shortcomings of the breakpoint system by producing a consistent high-pressure spark throughout the life of the engine, which means fewer engine misfires and reasonable emissions.
These electronic systems still use traditional distributor covers and distributor rotors to perform the same job of distributing current to the spark plug (so they are also distributor-based ignition systems).
Despite having fewer moving parts, the dispenser was also prone to wear and tear and eventually needed to be replaced – which prompted later ignition systems to further improve in this area. Another limitation of the electronic ignition system is that the ignition timing has not been precisely controlled as required by the manufacturer, resulting in slow acceleration and fuel inefficiency.
Automotive Ignition System Tutorial: How Electronic Ignition Works
Like the early open point ignition system, the electronic system has two ignition coils, so there are also two circuits, a primary circuit and a secondary circuit. The primary circuit portion of the primary coil remains the same from the cell to the battery terminals, as does the entire secondary circuit.
Wiring diagram of the electronic ignition system.
When the ignition switch is turned on, the battery low-voltage current flows from the battery through the ignition switch to the primary coil. Unlike the circuit breaker point in earlier systems, the current is interrupted and continuously reopened by a component called an armature, which has many “teeth” as it rotates through a pickup coil that acts as a sensor.
As each tooth of the armature approaches the pickup coil, it generates a voltage that signals the electronic module to turn off the current flowing through the primary coil. Essentially, this mechanism is very similar to that found in the circuit breaker point system.
When the current is interrupted, the magnetic field around the primary coil collapses, creating a high-voltage pulse in the secondary coil. Now the current runs on the secondary circuit, which is the same as in the circuit breaker point system. After the collapse of the magnetic field of the primary coil, the timing circuit in the electronic module will turn on the current again, and the whole process is repeated for each cylinder in the ignition sequence.
Summary of electronic ignition
Merit:
- Unlikely to fail: Circuit breaker points and condensers are removed, so there are fewer mechanically moving parts for the electronic system, making failure less likely.
- Reliable: Unlike circuit breaker ignition systems, electronic systems can produce consistent high-pressure sparks throughout the engine’s lifecycle, which means fewer engine misfires and reasonable emissions.
Shortcoming:
- Maintenance: Still, the dispenser is still there, and it will suffer wear and tear and need to be replaced, increasing the cost of repairs.
- Timing: The spark timing is precise, resulting in slow acceleration and poor fuel economy.
4 types of ignition systems: #3 dispenserless ignition
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One disadvantage of electronic ignition systems is that they still have distributors and are prone to wear and tear. In addition, dispensers tend to accumulate moisture and cause problems that are difficult to start. The distributor also needs engine power to rotate because it rotates synchronously with the engine, so the absence of a distributor means less engine drag and more efficiency.
The manufacturer came up with a solution: remove the fully mechanical distributor and replace it with a solid-state switch that does not wear out.
Doing so improves reliability, but the solid-state switch still receives the marching command from the distributor shaft, which is still mechanically rotated by the camshaft. And the splitter shaft is prone to wear and tear and tends to be problematic after about 120,000 miles.
Any wear and tear would have prevented proper ignition timing, so from the early 80s, manufacturers completely eliminated mechanical distributors and introduced a distributorless ignition system. These systems are very different from the breakpoint and electronic ignition systems, where the ignition coil is now located directly on top of the spark plug, eliminating the spark plug wires and making the system fully electronic.
A guide to how automotive ignition systems work: How dispenserless ignition works
The third type of ignition system is the distributor, also known as the waste spark ignition system. The system uses multiple ignition coils instead of the traditional fault distributor: one coil per cylinder or one per pair of cylinders.
The distributorless ignition system uses multiple ignition coils.
There is no distributor to “distribute” the current to the spark plug, which ignites directly from the coil. The spark plug timing is controlled by an electronic ignition module and an engine computer.
The system uses engine sensors to determine the crankshaft position and camshaft position. These sensors continuously monitor the position of the two axes and transmit this information to the engine computer.
The crankshaft position sensor is mounted on the front of the crankshaft, or near the flywheel in some vehicles, whereas the camshaft position sensor is installed near the end of the camshaft.
Depending on the position of the two axes, the electronic ignition module triggers the corresponding ignition coil and ignites the relevant spark plug directly. The system also uses a “waste spark” for one of the paired cylinders, pairing two pistons that are simultaneously at the top dead center: one at the end of the compression stroke and the other at the end of the exhaust stroke.
Another major difference compared to its predecessor is that while the earlier system used a single coil consisting of primary and secondary windings to power all cylinders in a specific order, the distributorless ignition system had a different coil setup. It uses multiple groups of ignition coils, each generating sparks for only two cylinders, which means that each coil can be left open for a longer period of time.
As a result, this soil setup is capable of producing a stronger magnetic field of up to 30,000 volts, as well as the stronger, hotter spark needed to ignite the lean air-fuel mixture typical of more modern vehicles.
Each spark plug in these cylinders will be simultaneously ignited using high pressure from one coil. This allows for more precise ignition timing, resulting in higher engine efficiency and lower emissions.
Summary of dispenser-free ignition
Merit:
- Reliable: Consistently high voltages can be generated throughout the life of the engine.
- Precise ignition timing: Emissions can be reduced by precisely controlling the ignition timing by removing the distributor that can be worn out after a certain mileage.
- Failure is unlikely: since there are no moving parts, because the system is now electronic.
Shortcoming:
- More expensive maintenance: However, the lack of moving parts also means that it is more difficult to diagnose and can be more expensive to repair than a mechanical ignition system if something goes wrong.
- More expensive parts: Distributor-less systems require dual platinum spark plugs to facilitate their ignition mechanism.
4 Types of Ignition Systems: #4 Coil-On-Plug Ignition
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What are the types of ignition systems? The coil-to-plug ignition system has all the advantageous electronic controls developed in a distributor-less system. In addition, like the distributorless system, the plug coil system places the ignition coil directly on top of each spark plug to ignite the spark plug directly, hence the name.
The spark plug coil ignition system uses multiple coils that are located directly on top of the spark plug.
Because each spark plug now has its own dedicated coil, located directly above the direct ignition, the high-voltage spark plug wire is completely removed. This increases the efficiency of the system, as spark plug wires cause greater amperage and voltage loss, and if they become greasy or frayed, there is a risk of contamination and cross-ignition between the cables.
Another major improvement here is that the two cylinders share a coil, and now only one cylinder is serviced per coil. This means that each coil can be “turned on” twice as long to produce the maximum magnetic field.
As a result, a plug coil ignition system can produce 40,000 to 50,000 volts and up to 30,000 volts in a distributor-less system, and can produce a hotter, stronger spark to burn leaner air-fuel mixtures more efficiently, maximizing engine efficiency.
There are now no circuit breaker points, distributors, condensers, and spark plug wires. The absence of moving parts means that coil-to-plug ignition systems are less likely to fail, more reliable and require less frequent servicing.
On the downside, it should be noted that once a problem does occur, the lack of moving parts makes diagnosis more difficult and more expensive to repair than with traditional systems, but as mentioned above, repairs are less frequent.
It should also be noted that the ignition coils are now on top of the spark plugs, making them more susceptible to damage from degreasers and water during engine cleaning under the hood, so make sure each coil is wrapped in plastic for protection before starting any cleaning.
Car Ignition System Tutorial: How Coil Plug Ignition Works
The most complex of all ignition systems, this system uses an engine control unit to control spark timing based on inputs from various sensors for optimal accuracy, higher voltages, and stronger, hotter sparks.
Similar to the distributorless system, the plug coil system uses engine sensors to know the position of the shaft. Based on this information, the engine control unit triggers the corresponding ignition coil, which directly ignites the relevant spark plugs in the relevant cylinders in the firing order.
Coil-On-Plug Ignition Summary
Merit:
- Engine Efficiency: Can produce consistent, high voltages and hotter, stronger sparks that can efficiently burn thinner air-fuel mixtures in newer vehicles.
- Precise ignition timing: This results in optimal engine efficiency and lower emissions.
- Less frequent repairs: Since the spark plug wires are now removed, moving parts are missing.
Shortcoming:
- Repairs: The absence of moving parts means troubleshooting is difficult and more expensive repairs.
As technological advancements lead to continuous improvements, ignition systems will continue to improve with features that are unimaginable today. Even so, all four types of ignition systems are still easy to maintain and repair, making them ideal for vehicles of their respective eras.
To learn more about the important components in your valuable vehicle and how they work, dive into our comprehensive maintenance tips article.v
