With the vast variety of automotive applications, the ignition system has a vital role as it generates a spark. It heats an electrode to a high temperature so that the fuel-air mixture can be ignited in all spark-ignition internal combustion engines.
Some automobiles, including stationary and movable applications, are also designed with the system, which may include gas-fired and oil-fired boilers, rocket engines, etc. This is the reason why various types of ignition systems have been in existence.
Well, in this reading, we’ll explore what an ignition system is, its applications, functions, parts, diagrams, types, and how it works. We’ll also explore its advantages and disadvantages.
Let’s get started!
What is an Ignition System?
An ignition system is a system used in some types of an internal combustion engine, often a petrol engine, to ignite the fuel-air mixture. This ignition is purposely performed so that the explosion in the combustion chamber can be accomplished.
This is to say, the spark that occurs in the ignition system (spark plug) causes the fuel-air mixture to burn.
Just as earlier mentioned, the ignition system is featured in spark-ignition internal combustion engines, although it’s also employed in some other mechanical applications. But it’s quite popular on the gasoline engine.
Compression heat ignites the fuel-air mixture in compression ignition diesel engines, which is a different process that results in the removal of the spark plug. This is another topic of discussion you can check out!.
Induction Coil Systems
As batteries started to appear more frequently in automobiles (as a result of the increased use of electric starter motors), systems using an induction coil took their place.
The 1908 Ford Model T and the 1886 Benz Patent-Motorwagen both featured a tremble coil ignition system, in which the tremble disrupted the current through the coil and generated a flurry of sparks during each firing.
At the proper time during the engine cycle, the tremble coil would turn on. The four-cylinder engine of the Model T has a tremble coil for each cylinder.
Distributor-Based Systems
Charles Kettering created a better ignition system at Delco in the United States, and it was first used in Cadillac’s 1912 vehicles.A single ignition coil, breaker points, a capacitor (to stop the points from pulling at break), and a distributor (to send the right amount of current from the ignition coil to the right cylinder) made up the Kettering ignition system.
Due to its reduced price and relative simplicity, the Kettering system became the standard ignition system in the car industry for many years.
Function of an Ignition System
Below is the function of an ignition system in spark-ignition internal combustion engines:
- The primary function of an ignition system is to create an electric spark in the engine combustion chamber at the proper time so that the gasoline and air mixture can ignite.
- It produces 30,000 volts across the spark plug.
- A high-voltage spark is supplied to each spark plug in the correct sequence.
- There is different spark timing with load, speed, and other conditions.
- The spark is timed so it can occur as the piston is approaching the top dead center.
Applications
Below are the applications of the various types of ignitions system in automotive engines:
- The system is used in two-wheeler vehicles (SI engines).
- Just as the battery is used to generate power in the battery ignition system, magneto is used for the generation of electricity.
- Finally, the ignition system is widely used in applications such as tractors, outboard motors, washing machines, marine engines, power units, and natural gas engines.
Related: What Is A Car Battery? Its Diagram, Types And How It Works
Components of an Ignition System
Below are the various parts of different types of ignition systems and their functions:
Magneto ignition system: The components of the magneto ignition system include a magneto, distributor, capacitor, cam, contact breaker, and ignition switch. Their function has been explained in the full article.
Battery ignition system: The components of the battery ignition system are the ignition switch, the ignition coil, and the ballast resistor. Its components also contain a contact breaker, distributor, capacitor, and spark plug. Check the full article to see their function. Finally,
Electronic ignition system: components of the electronic ignition system also include a battery, distributor, capacitor, ignition control module, armature, ignition coil, and spark plug.
The major components of an ignition system are the storage battery, an induction coil, a distributor, and a spark plug. You’ll also need a device to generate timed high-voltage discharges from the induction coil.
The function of the storage battery is to provide an electric current of low voltage (often 12 volts). The 12 volts will be converted by the system to high voltage of about 40,000 volts.
The distributor the direct the high-voltage current to each spark plug in the firing order.
Diagram
Types of ignition system
Below are the three basic types of ignition systems used in spark-ignition internal combustion engines:
Magneto ignition system
In magneto types of the ignition system, magneto serves as the major component used for creating the energy of high voltage. This high voltage is then used for the generation of electricity, which is further used to run vehicles.
The system is a combination of a distributor and a generator built as one unit. This makes it different from the conventional distributor that creates spark energy without external voltage.
Electronic Ignition System
The electronic types of ignition system are fully controlled electronically and are powered by a battery, unlike the previous one that used magneto.
It has negative and positive terminals; the negative terminal is grounded while the positive is connected to the ignition switch. So, when the switch is on, power is supplied to the electronic ignition module through the wires.
The power is then sent to the ignition coil, that has two windings: primary winding and secondary winding. These windings are insulated and the primary is thicker than the secondary winding. There is a rod between the windings that generates a magnetic field. Finally,
Battery Ignition System
The battery types of an ignition system are widely used in automobiles to produce sparks using spark plugs with the aid of a battery. It’s often found in 4-wheeler vehicles but is now used in two-wheeler vehicles that obtain current from a 6-volt or 12-volt battery in the ignition coil.
Related: What Is A Carburetor? Its Function and How It Works
How Does an Ignition System Work?
The working of an ignition system is less complex and can be easily understood. It is obvious with the above explanation of the above sections that you are now familiar with the functional parts and the operation of the system.
The ignition system of a car must ignite the fuel at exactly the right time for the exploding gases to do the maximum work. Emissions might increase if the ignition system fires at the wrong time.
The fuel/air mixture has been completely used, and the pressure in the cylinder reaches its optimum after a slight delay from the time of the spark.
The primary and secondary windings of the ignition coil in an engine receive power from the battery.
A magnetic field is generated by an iron rod between the windings, which intensifies as the armature rotates. This voltage signal is then sent to the distributor, which houses a rotor and distributor points set according to ignition timing.
As the rotor aligns with the distributor point, the voltage jumps through the air gap and is transmitted to the spark plug terminal via a high-tension cable, generating a spark at the spark plug’s tip and initiating combustion.
If the spark occurs at the exact moment the piston reaches the top of the compression stroke, the piston will have already moved a portion of the way into its power stroke before the gases in the cylinder have reached their peak pressures.
In order to maximize fuel usage, the spark should occur prior to the piston reaching the highest point of the compression stroke. This ensures that the pressures are sufficiently lifted to begin useful work when the piston begins its power stroke.
Advantages and Disadvantages of Ignition System
Advantages:
Below are the benefits of the ignition system:
- Less maintenance is required in magneto ignition systems; it’s less expensive, occupies less space, and does not require a battery. It has high working efficiency due to high-intensity spark and is less prone to error as the battery is not used
- Another advantage of ignition systems is that the choice of electronic types has fewer parts and also required low maintenance. Its efficiency is also good and it generates less emission. Another advantage of the electronic ignition system is that it increases fuel efficiency. Finally,
- The advantage of battery-type ignition systems is that there is good intensity of spark. It also provides a high concentration of spark even when the engine speed is low or at first starting. It also has less maintenance, just like other types of ignition systems.
Disadvantages:
- The disadvantage of the magneto type of ignition system is that there is a poor quality of spark at first start of low speed. Misfiring might also occur due to leakage and the cost of the system is high.
- Disadvantages of the electronic types of ignition systems are that the cost of the system is dramatically high and can occupy much space as a battery must be used to power the system.
- In the battery, the disadvantages include periodic maintenance for the battery alone, more space occupied, and efficiency decreased with a reduction in spark intensity.