Lighting and Electronics
Hella uses the various synergies and knowledge drawn from the fields of lighting engineering and electronics to develop complete holistic systems.

The range currently in series production:
- Xenon headlamp systems
- manual headlamp levelling 
(electric, pneumatic, and hydraulic systems)
- automatic headlamp levelling devices 
(quasi-static, dynamic)
- vehicle levelling sensors 
(magneto-resistive, inductive)
- lamps with integral electronic systems
(LED lamps, interior lamps). 

  Electronic control unit and headlamp levelling device for a xenon headlamp
 
Innovations
- Bi-Xenon systems (projection and reflection systems) and Vario-Xenon systems
- headlamp levelling control units with integrated inductive vehicle levelling sensor
- non-contact vehicle levelling sensor systems
- actuator and sensor systems for AFS (Advanced Frontlighting Systems) and ARS (Advanced Rearlighting Systems).
- combination rear lamps with integrated electronics
  Sensor-integrated headlamp levelling control unit
 
Xenon headlamp systems
Hella, working in close collaboration with car manufacturers, has had an enormous influence on the development and introduction of Xenon light in motor vehicles. An electronic booster unit, which is constantly being improved in terms of cost and construction space, controls the start-up of the light and maintains a constant performance output as well as dealing with any malfunction. In addition to reliability, service life, and the safety concept, other major advantages are the lower energy consumption, smaller volume, and decreased weight of Xenon lights.

 

   The development of xenon ballast units
 
Statutorily-required components such as headlamp cleaning systems and automatic headlamp-levelling devices are all part of Hella's product range, thus enabling Hella to supply complete coordinated systems as one, highly efficient product.

Newly developed mechatronic component groups for reflection and projection systems make it possible to install just one Xenon light source for each headlamp, providing both main and dipped beams - a great saving in space. The Vario-Xenon system represents a further development, with more than two lighting functions. 

In the Bi-Xenon projection module, the light from the Xenon lamp is projected onto the road through a lens. Rotating a shield (shown here in blue) increases the light aperture size beyond the dipped-beam area and also projects the broad and long-range light as xenon light, with a colour similar to that of daylight. 

   Mechatronics for a Bi-Xenon projection module
 
Manual and automatic headlamp range adjustment 
Hella offers the best possible solutions to each task set by any individual customer's specifications.

Manual headlamp range adjustment involves not only hydraulic and pneumatic systems but also in particular 3rd-generation electric systems, which offer weight and volume savings. A distinction has to be made regarding automatic headlamp levelling systems between static systems, which correct for angular differences resulting from changes in the load; and dynamic ones, which also react to braking and acceleration movements. 

 

   Block diagram of headlamp levelling system
 
The systems consist of freely programmable control units, actuator elements on the headlamps, and vehicle level sensors which register the depression of the suspension at the axles. 

In addition to the magneto-resistive sensors, Hella has also developed a new inductive vehicle level sensor, the distinguishing features of which are its high degree of accuracy and its great flexibility. 

Lighting with integrated electronic systems
In addition to developing interior lighting with simple functions such as delayed-action switches, lamps are also suitable places for housing supplementary electronically controlled functions. 

   Comparison between unregulated and regulated (dynamic) headlamp levelling systems

Components of a dynamic headlamp levelling system
 
Light-emitting diodes
The advantages of LEDs (light-emitting diodes) - their long service life, short response times, low energy consumption, and flat construction - and the continual improvements in their light output have caused LEDs to be increasingly used, particularly in the field of signal lighting.

Electronic functions are necessary in connection with front and rear lamps for monitoring and controlling flashers, as well as dimming. 

Changing the car's wiring network structure, to the extent of integrating combination rear lamps into a BUS network, leads to a greater degree of integration in the supplementary electronic functions: 

- switching on the lighting functions and neighbouring energy-consuming sources
- flasher-unit function with monitoring and synchronisation
- features such as double-flashing, dimming functions, lamp monitoring, etc.

 
Centre high-mounted brake light