The Effect of Impact on the Filaments of Quartz Halogen Headlamps

Abstract

ABSTRACTQuartz halogen headlamps, unlike the older types of sealed beam headlamps, often have filaments oriented parallel to the forward direction of travel of the vehicle. Both compression and stretching of filament coils may be observed when vehicles equipped with quartz halogen headlamps are involved in collisions. The conditions under which these distortions occur have been studied by conducting impact tests on quartz halogen lamps under known conditions of velocity, illumination and impact angle. The results show that filament coil compression distortion was produced by the “head-on” impact of illuminated filaments, whereas coil stretching distortions were produced by impact of illuminated filaments at any angle. Further, if impact forces are of sufficient magnitude, an illuminated filament in an intact quartz halogen lamp can break.