Ignition coil (VAZ-2106)

The contact ignition system uses an ignition coil of the B-117A type. The ignition coil is used to convert a low-voltage current of 12 V into a high-voltage current of 11-20 kV, which is necessary to break down the air gap between the spark plug electrodes and form a spark that ignites the working mixture. The coil is installed in the engine compartment and is fastened with nuts on two studs to the left mudguard. It is a transformer with a magnetic circuit consisting of a core and an outer magnetic circuit, and two windings - primary and secondary. The core is assembled from electrical steel plates and is located in a frame on which the secondary winding is wound. The primary winding is wound through an insulator over the secondary winding. The outer magnetic circuit consists of a rolled-up tape of electrical steel. The coil housing is steel, it has a cylindrical shape. From above, the housing is hermetically sealed with a lid made of insulating material. Transformer oil is poured into the housing to improve cooling and insulation. The coil cover contains a high-voltage and two low-voltage terminals. The high-voltage terminal is connected to the secondary winding and, through a contact bolt and spring, to the core. The end of the primary winding is connected to one low-voltage terminal of the coil, connected by a wire to the ignition distributor contact group. Voltage from the ignition switch is supplied to the "+B" terminal of the coil.

The current flowing through the primary winding of the ignition coil creates a magnetic field around the coil turns. When the breaker contacts open, the current in the primary coil circuit disappears, the magnetic field is sharply reduced and, crossing the turns of the primary and secondary windings, induces an electromotive force (EMF) in them proportional to the number of turns. In the secondary winding, the EMF reaches 12,000-24,000 V, and in the primary - 200-300 V.



The contactless system uses coils of type 27.3705 (open-circuit, oil-filled) or type 3122.3705 (with closed magnetic circuit, dry).

Original source is on the resource VazBook.ru