In usual system of ignition the ignition coil develops a power-current and the ignition distributor transfers this current during demanded time to corresponding spark plug.
In contactless system of ignition the gauge of position of a camshaft and the gauge of an angle of rotation of a cranked shaft hand over to the block of engine management the information in what cylinder it is necessary to submit pressure of ignition. The engine management block gives a signal to corresponding coil of ignition which develops a power-current and transfers this current to a spark plug.
In contactless system of ignition the ignition impulse moves at once on two spark plugs, one on the compression step, one on an exhaust step – the ignition spark on a step of an exhaust does not render any value for engine work and consequently is spent for nothing. Cylinders are grouped according to an operating procedure of cylinders. For example, an operating procedure of cylinders – 1–3–4–2. Each coil of ignition actually consists of 2 separate high-voltage windings which submit a spark to two cylinders everyone (one to cylinders № 1 and 4, and another to cylinders № 2 and 3).
If at such system of ignition to connect an inductive tachometre to a high-voltage wire of a spark plug, it will show frequency of rotation of a cranked shaft of the engine twice more than actual frequency of rotation (i.e. 1600 mines-1, instead of actual 800 mines-1).
Electronic system of an advancing of ignition
Installation of a corner of an advancing of ignition is defined and established by the block of management of the engine based on signals from various gauges and switches.
The engine management block changes installation of a corner an ignition advancing according to frequency of rotation of the engine, quantity of arrived air, temperature of a cooling liquid and other conditions.
Corner of an advancing of ignition on frequency of idling: 8±5 ° to ВМТ (6°± 5 ° for Europe).
The corner of an advancing of ignition is not regulated.