What is the function of an ignition coil?
1 Answers
The function of an ignition coil is to convert the 12V low-voltage electricity from the power source into 15–20kV high-voltage electricity. This high-voltage electricity is then transformed into a high-voltage spark by the spark plug, igniting the combustible air-fuel mixture. The working principle of an ignition coil: 1. The reason an ignition coil can convert the low-voltage electricity from the vehicle into high voltage is due to its similar structure to a conventional transformer, with a large turns ratio between the primary coil and the secondary coil. 2. However, the operation of an ignition coil differs from that of a conventional transformer. While a conventional transformer can operate continuously, an ignition coil works intermittently, repeatedly storing and releasing energy at varying frequencies depending on the engine's speed. 3. When the primary coil is connected to the power source, a strong magnetic field is generated around it as the current increases, and the iron core stores this magnetic energy. When the switching device disconnects the primary coil circuit, the magnetic field of the primary coil rapidly decays, inducing a very high voltage in the secondary coil. 4. The faster the magnetic field of the primary coil disappears, the greater the current at the moment of disconnection, and the larger the turns ratio between the two coils, the higher the voltage induced in the secondary coil.
