Active Dimming System

The control unit for the active dimming system uses sensors to adjust the interior lighting of a vehicle based on exterior light conditions. The control unit can be set for minimum lighting requirements, in which case the desired lighting level is obtained by the optimal use of the lights, that is, with minimal energy consumption. The active dimming of both LED and fluorescent lights works with the Teknoware electronic unit.
The smart adjustment algorithm of the controlling unit reacts in all different kinds of situations so that passengers do not even notice the changes in lighting. The algorithm could be defined together with the client to reach all necessary requirements.

The main target of the active dimming system is to save energy during the daytime by decreasing artificial light inside the vehicle when daylight is available. Light sensors inside the vehicle measure the light levels, and the intelligent light control unit dims the artificial light when light levels are higher than required. The required level is set in the manufacturing phase of the vehicle and the required levels could also be preset at any time afterwards with a suitable adjustment tool. The required levels are stored in the non-volatile memory of the intelligent light controller for the active dimming system.


The achieved energy savings through the active dimming system could be as high as 40% per year. The amount of energy saving depends on the region where the vehicle operates.

Energy savings is not the only benefit of the active dimming system. The lifetime of the light sources will also be longer. A longer lifetime is possible because the light sources can operate at lower power levels during most of the day. For example, with LED lights, the lifetime increase could be as remarkable as a doubled lifetime. This is especially so at daylight time when temperatures outside the vehicle and inside the roof of the vehicle are much higher than during the night. The active dimming system reduces the temperature of the LEDs by reducing their power. It is commonly known that temperature has the strongest influence on the lifetime of LEDs.