Principle of ignition coil
A typical ignition coil has two sets of coils, a primary coil and a secondary coil. The primary coil uses thicker enameled wire, usually wrapped around 200-500 turns with enameled wire of about 0.5-1 mm; The secondary coil uses thinner enameled wire, usually wrapped around 15000-25000 turns with approximately 0.1 millimeters of enameled wire. 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 (circuit breaker). One end of the secondary coil is connected to the primary coil, and the other end is connected to the output end of the high-voltage line to output high-voltage electricity.
The reason why the ignition coil can convert low voltage electricity in the car into high voltage is because it has the same form as a regular transformer, with the primary coil having a larger turns ratio than the secondary coil. But the working mode of the ignition coil is different from that of ordinary transformers. The working frequency of ordinary transformers is fixed at 50Hz, also known as power frequency transformers, while the ignition coil works in the form of pulses, which can be regarded as pulse transformers. It repeatedly stores and discharges energy at different frequencies according to the different speeds of the engine.
When the primary coil is powered on, a strong magnetic field is generated around it as the current increases, and the iron core stores magnetic field energy; When the switch device disconnects the primary coil circuit, the magnetic field of the primary coil rapidly decays, and the secondary coil will induce a high voltage. The faster the magnetic field of the primary coil disappears, the greater the current at the moment of current interruption, and the larger the turn ratio between the two coils, the higher the voltage induced by the secondary coil.
The reason why the ignition coil can convert low voltage electricity in the car into high voltage is because it has the same form as a regular transformer, with the primary coil having a larger turns ratio than the secondary coil. But the working mode of the ignition coil is different from that of ordinary transformers. The working frequency of ordinary transformers is fixed at 50Hz, also known as power frequency transformers, while the ignition coil works in the form of pulses, which can be regarded as pulse transformers. It repeatedly stores and discharges energy at different frequencies according to the different speeds of the engine.
When the primary coil is powered on, a strong magnetic field is generated around it as the current increases, and the iron core stores magnetic field energy; When the switch device disconnects the primary coil circuit, the magnetic field of the primary coil rapidly decays, and the secondary coil will induce a high voltage. The faster the magnetic field of the primary coil disappears, the greater the current at the moment of current interruption, and the larger the turn ratio between the two coils, the higher the voltage induced by the secondary coil.
