Distribute ignition — design description

Bosch ignition distributor

The impulse sensor with a Hall converter is located in the ignition distributor, replacing the classic breaker. It also includes: a fixed, so-called magnetic partition and a rotor. The magnetic partition is formed by a permanent magnet fixed on a fixed plate, as well as a Hall transducer located opposite the pole of the permanent magnet on a ceramic element.

The rotor has the shape of a low cylinder, in the cylindrical part of which four rectangular cutouts are made. During the rotation of the rotor, its cylindrical part passes between the magnet pole and the Hall transducer, interrupting and deflecting the magnetic flux four times per revolution, each time causing the formation or disappearance of the Hall effect. When the Hall effect disappears, the switch transistor passes current through the primary winding of the ignition coil, and the appearance of a magnetic flux causes the Hall effect and interruption of the current flow (similar to opening the breaker contacts in a classic ignition distributor). At the moment of the disappearance of the current in the primary winding, a high voltage is induced in the secondary winding of the ignition coil, transmitted through the distributor to the spark plug of the corresponding cylinder.


The described solution has two important advantages: there is no mechanical wear, and therefore no adjustment is required, and the energy of the ignition spark is provided almost independently of the engine speed (in the classical system, the spark energy decreases with a high engine speed).

The ignition distributor of the Bosch transistor system, like the classic distributors, is equipped with ignition timing regulators: centrifugal and vacuum. Whereas the Lucas transistor system ignition distributor does not have these controls.

Attention! Do not replace the original distributor rotor to maintain the proper resistance.