Optical sensors for automotive applications

The authors describe the development of two automotive sensors by a co-operation between First Inertia Switch Ltd. and Sira R&D. The sensors in question were an automatic headlamp dipswitch, and a steering wheel rotation sensor. In both cases FISL provided the impetus and marketing strengths to maintain focus on the requirements, and Sira provided a design and development resource to meet the technical challenge. The automatic headlamp dipswitch is a device that changes the headlights from main beam to dipped beam when a bright source (e.g. oncoming car headlamps) are in the field of view. It consists of a lens, aperture plate, photocell and processing circuitry. The steering wheel rotation sensor consists of a launcher, light collectors, and electronic processing. It uses IR LED technology. The authors briefly describe how each sensor works