The majority of cars on the road today use headlights, signaling lights, and interior lights that send electricity through a tungsten filament to create light.
As the current flows through the filament, it encounters the resistance in the filament windings and gets very hot.
It eventually gets so intense that the filament starts to glow and emits a light.
Halogen lighting
Headlight bulbs that use tungsten filaments are usually filled with halogen gas, so they’re referred to as ‘halogen headlights.’
Many consumers believe that ‘halogen headlights’ are an upgrade, but in reality, virtually every tungsten filament headlight in the US has used halogen gas since the 1980s.
