Explain in details the ignition system
The ignition system is a crucial component of a gasoline engine that initiates the combustion process, allowing the engine to start and function properly. Its main purpose is to generate and deliver a high-voltage electrical spark to ignite the fuel-air mixture in the combustion chambers of the engine.
The key components of an ignition system include the ignition coil, distributor (or electronic ignition module), spark plugs, and the associated wiring. Let's dive into each of these components in detail:
1. Ignition Coil: The ignition coil is responsible for transforming the low-voltage electrical current from the battery into a high-voltage current needed to create a spark. It utilizes electromagnetic induction principles to do so. The coil consists of primary and secondary windings, where the primary winding is connected to the battery via a switch. When the switch is closed, a current flows through the primary winding, creating an electromagnetic field. When the switch is opened, this field collapses, inducing a high-voltage current in the secondary winding.
2. Distributor/Electronic Ignition Module: The distributor (older ignition systems) or electronic ignition module (modern systems) is responsible for accurately delivering the high-voltage current from the ignition coil to the spark plugs in the correct firing order. It ensures that the spark occurs at the right time for each cylinder. In older systems with a distributor, it contains a rotor that spins, directing the high voltage generated by the coil to each spark plug wire connected to individual cylinders. Electronic ignition modules, on the other hand, perform this function through electronic controls without the need for moving parts.
3. Spark Plugs: Spark plugs are installed at the top of each cylinder in an engine and provide the spark needed to ignite the fuel-air mixture. They consist of a metal center electrode surrounded by an insulator and a metal ground electrode. When the high voltage is delivered by the distributor or electronic ignition module to the spark plug, a spark jumps across the gap between the center and ground electrodes, igniting the compressed fuel-air mixture in the cylinder.
4. Wiring: The ignition system functions by establishing a complete electrical circuit that allows the flow of current from the battery to the primary winding of the ignition coil and then to the distributor or electronic ignition module. Appropriate wiring, including high-tension ignition wires, is used to connect the various components of the system, ensuring that the high voltage is properly delivered to the spark plugs.
To summarize the process, the ignition system begins when the driver turns the key or presses the start button, closing the switch and allowing current to flow through the primary winding of the ignition coil. When the switch is opened, the collapsing electromagnetic field induces a high voltage in the secondary winding. This high voltage is transmitted to the distributor or electronic ignition module, which then delivers the voltage to the spark plugs in the correct firing order. The spark plugs generate a spark to ignite the fuel-air mixture in each cylinder, kickstarting the combustion process and allowing the engine to run.