The principle of operation of the ignition system (VW Passat B2)

The magnetic part of the ignition distributor sensor, called the generator control pulse sensor, consists of the actual magnetic Hall sensor and a toothed anchor fixed to the rotor.

The magnetic flux in the ignition coil changes depending on the passage of the anchor teeth rotating in the interpolar gap of the magnetic sensor. When the anchor tooth enters the interpolar gap, the magnetic field in the integrated circuit of the Hall sensor is absent, and there is no induced current. When the anchor tooth leaves the interpolar gap, in accordance with the law of induction, an alternating voltage arises in the Hall sensor circuit, the circuit closes and a control pulse is formed.

The width of the anchor teeth corresponds to the angle of the cam.

The switch controls the ignition depending on the rotation speed of the ignition distributor shaft, the battery voltage, the total resistance of the ignition coil, and in any engine operating mode it produces constant voltage pulses.

Interruption of the current in the primary winding of the ignition coil by the commutator causes a sharp change in the magnetic flux in the coil and the appearance of a high voltage current in the secondary winding of the ignition coil.

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