An electronic ignition system is an ignition system for automobile engines that uses electronic components to control ignition timing and ignition energy. Traditional mechanical ignition systems have been replaced by electronic ignition systems as the latter offer greater accuracy and reliability.
Electronic ignition systems usually consist of the following main components:
Control module (ECU): The electronic control unit is the brain of the system, responsible for monitoring engine operating status and sensor data, and controlling ignition timing and ignition energy based on this information. The ECU is also able to adapt to different driving conditions and environments to optimize engine performance and fuel efficiency.
Ignition Coil: The ignition coil converts the low voltage provided by the battery into high voltage, which is used to generate the ignition spark. The ignition coil in an electronic ignition system usually consists of two parts. The primary coil is a thicker coil, usually wrapped in an iron core. It is connected to the battery or power source and is responsible for receiving low voltage current. When the control module sends a signal, the current in the primary coil is cut off or switched on and off, creating a change in the magnetic field. The secondary coil is a thinner coil that is wound around the primary coil and usually has more turns than the primary coil. When the current in the primary coil is cut off, the magnetic field in the secondary coil changes, causing an increase in voltage. This change results in a high voltage pulse across the secondary coil, which is the electrical spark used to ignite the ignition in the ignition system.
Sensor: The sensor is used to monitor various parameters of the engine such as Crankshaft Position: This sensor monitors the position and rotational speed of the crankshaft. It provides information about the crankshaft angle to the control module to help determine ignition timing. Cylinder pressure: Used to measure atmospheric pressure, helping the ECU calculate the impact of altitude and air pressure changes on engine performance, and adjust ignition timing and fuel injection accordingly. Intake air temperature: Measure the temperature of the air in the intake pipe. This information can be used to adjust fuel injection and ignition timing to suit engine operating conditions at different temperatures. Engine Cooling Temperature: Measures the temperature of the coolant so that the control module can adjust ignition timing and fuel injection to accommodate changes in engine temperature. The data provided by these sensors can help the ECU determine the best ignition timing and ignition energy.
Engine Position Sensor: This sensor is usually a rotary sensor that monitors the position and speed of the crankshaft. It provides the basic positioning information of the engine to the ECU in order to calculate the ignition timing.
Electronic distributor (distributor): In some types of electronic ignition systems, a distributor is used to control the distribution of spark, ensuring that each cylinder produces spark at the correct time.
Advantages of electronic ignition systems include greater reliability, better combustion efficiency, reduced maintenance requirements and better emissions control. They also make it easier for automakers to implement advanced features such as adaptive ignition control and diagnostics.