The functions and classification of ignition coils
The function of the ignition coil is to convert low-voltage direct current into high-voltage electricity. Then the spark plug in the cylinder uses this electricity to produce electric sparks. There are two types of ignition coils: open magnetic circuit ignition coil and closed magnetic circuit ignition coil.
The function of the ignition coil is to generate electric sparks in the cylinder in a timely, accurate, and reliable manner when the engine is in various working and usage conditions, in order to ignite the combustible mixture and enable the gasoline engine to work.
Specifically, the function of the ignition coil is to convert the 12V low voltage of the power supply into 15-20kV high voltage electricity. The high voltage electricity is converted into a high voltage spark through the spark plug to ignite the combustible mixture. The camshaft and crankshaft position sensors determine the ignition timing.
The reason why the ignition coil can turn the low voltage of the vehicle into high voltage is because it has the same form as a regular transformer, with a large turn ratio between the primary and secondary coils. But the working mode of the ignition coil is different from that of a regular transformer. Ordinary transformers work continuously, while ignition coils work intermittently. It repeatedly stores and releases energy at different frequencies based on different engine speeds.
When the primary coil is energized, a strong magnetic field is generated around it due to the production of electric current, and the iron core stores magnetic field energy. When the switching device disconnects the circuit of the primary coil, the magnetic field of the primary coil rapidly decays, and a high voltage is induced at the secondary coil. The faster the magnetic field of the primary coil disappears, the greater the current at the moment of current disconnection. Also, the greater the ratio of turns between the two coils, and the higher the voltage induced by the secondary coil.
