Today we introduce the ignition coil in the car. Let’s go back to the basic: what is the principle of the ignition coil?
As the name implies,the ignition coil is the most critical part of the engine’s work to supply power to the spark plug, and generate sparks to ignite the compressed mixture. It is actually a transformer responsible for converting the low-voltage current of the vehicle into high-voltage electricity. Normally, each cylinder is equipped with a set of ignition coils. And spark plugs, ignition coils are generally replaced at 100,000 kilometers or even longer.
- How to generate high voltage above 10,000 volts
This starts with its structure. If you don’t understand this, you can check the structure of the ignition coil. There are two sets of coils in the ignition coil, the primary coil and the secondary coil. The primary coil uses thicker enameled wire, usually around 0.5-1mm enameled wire for about 200-500 turns; the secondary coil uses thinner enameled wire, usually around 0.1mm around 15000-25000 turns. One end of the primary coil is connected to the low-voltage power supply (+) on the vehicle, and the other end is connected to the switch device (breaker). One end of the secondary coil is connected with the primary coil, and the other end is connected with the output end of the high-voltage line to output high-voltage electricity.
When the primary coil is powered on, a strong magnetic field is generated around as the current increases, and the iron core stores the magnetic field energy; when the switching device disconnects the primary coil circuit, the magnetic field of the primary coil decays rapidly, and the secondary coil A high voltage will be induced. The faster the magnetic field of the primary coil disappears, the greater the current at the moment when the current is disconnected, and the greater the turns ratio of the two coils, the higher the voltage induced by the secondary coil.
- Similarities and differences between ignition coils and ordinary transformers
Both the ignition coil and the transformer can turn low voltage into high voltage, but the working mode of the ignition coil is different from that of the ordinary transformer. The working frequency of the ordinary transformer is fixed at 50Hz, also known as the power frequency transformer, while the ignition coil works in the form of pulses. It can be regarded as a pulse transformer, which repeatedly stores and discharges energy at different frequencies according to different engine speeds.
Generally speaking, when the engine at low speed, the magnetic field can reach saturation, and when the engine is high speed, due to the shortening of time, the magnetic field cannot reach saturation, the secondary voltage generated will be insufficient, and the spark will be weakened.
After understanding this, you can become an ignition coil expert by studying the following articles. I hope these articles can help you in your future work and life.
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