How does an ignition system work?

The working principle of the ignition system is that the engine computer controls the coil's primary current by controlling the grounding of the coil's primary circuit (the ignition system consists of the ignition coil, the distributor, the secondary ignition wire, and the spark plug). The computer controls the ignition advance angle according to different working conditions, so that the power, fuel consumption and emissions reach the best standard. The details are as follows:When the primary circuit is grounded, the current through the coil's primary winding generates an electromagnetic field. When the primary circuit is grounded and disconnected: the magnetic field is weakened and a high voltage (25kv~35kV) is induced in the secondary winding. The combustible mixture is then ignited by the high voltage arc between the spark plug electrodes.