The composition of the ignition coil

　　The ignition coil is mainly composed of an iron core, primary and secondary coils, bakelite cover, porcelain cup, and so on.

　　The iron core is made of laminated silicon steel plates and wrapped in a cardboard sleeve.

　　A secondary coil is wound on the paper sleeve, and the wire is an enameled wire with a diameter of 0.06 to 0.10 mm and is wound around 11,000 to 23,000 turns.

　　To enhance the insulation, the secondary winding is also covered with several layers of cable paper. The outside of the primary winding is conducive to heat dissipation. The diameter of the enameled wire is generally 0.5 to 0.8 mm, and it is wound around 220 to 330 turns. The outside is also covered with several layers of insulating cable paper.

　　There is also a steel sleeve for magnetic conductivity between the primary coil and the casing. There is an insulating porcelain cup on the bottom of the shell, and a bakelite cover on the upper part. There are shaped high edges around the inside of the bakelite cover to ensure the insulation performance of the high-voltage joint.

　　The shell is filled with insulating oil or asphalt to enhance the insulating performance and prevent the intrusion of moisture.

　　The selection of the ignition coil should be consistent with the polarity of the battery connection, which is conducive to reducing the working voltage of the spark plug and improving the ignition performance.