Ford Focus>> Ignition system>> General information>> Signals of the SKR sensor are a basis for formation of a spark

Fig. 211. Sensor of provision of a cranked shaft: 1 — the sensor; 2 — segments on a flywheel

As settlement base for RSM the signal of the sensor of an angle of rotation of a cranked shaft (SKR) serves. RSM operates primary winding of the coil of ignition after will transfer SKR signal to a digital form. RSM for short time interrupts a current in primary winding, as a result the high-tension current moves to spark plugs (fig. 211) .
The RSM block defines the optimum moment of ignition in each cylinder.
The ignitions given of the various moments, and also all characteristics of the external units participating in work of system of ignition are stored in his memory. For example, it processes SKR sensor signals at Zetec-SE engines and signals of the sensor of a detonation (KS). The current signals of the sensor of an angle of rotation of a cranked shaft are constantly compared to RSM put in memory this. Before giving command for an iskroobrazovaniye, the control unit the power unit processes the data received from separate elements of system of injection of fuel, such as the oxygen sensor, the sensor of a mass consumption of air, the sensor of frequency of rotation of a cranked shaft, and also from various temperature sensors.
Depending on load of the engine (idling, the partial loading, full loading) and amounts of fresh air the working mix in the chamber of combustion burns down with various speed. In order that as it is possible to use better energy from fuel combustion, the control unit changes the ignition moment for each separate cylinder, depending on load of the engine.