The light-range control should prevent the blinding of the oncoming traffic caused by the various loading conditions of the vehicle. An automatic regulation e.g., with Xenon light is mandatory. This system must be able to react relatively quickly, to any changes caused by the spring-compression.

With the automatic light-range control, the position of the unit is recorded by an inductive level-sensor and the control device gives the respective signals to the electric motors. A level-sensor can be seen in figure 2 above. It is mounted on the left front and rear in the vicinity of the wheel suspension. A small lever connects a movable rod to one the steering arms. During the spring compression, the small lever is, more or less, redirected. The electric signal is processed by the control device and the two servo motors align the headlights according to the incline of the vehicle.

The dynamic automatic system is capable of chosing from two speed ranges for the adjustment. It generally functions somewhat damped, e.g., to avoid an over-reaction. Should however, e.g., when accelerating or braking, a quick adjustment of the headlights be necessary, the servo motors can react in fractions of a second.

Vehicles fitted with level regulation generally don't need light-range control, because the vehicle's suspension always returns to its initial position. In general, when checking a system which has light-range control, one must ensure that the equipment is in the initial position (reset). The drivers seat must of course, also be occupied. 05/11