The general lighitng inside the coaches is provided by 110V DC or 110V AC supply. The supply system is backed up by battery system of 110V DC for self generation type coaches. During extreme emergencies like derailment, accidents etc. sometimes these supply system fail, causing total darkness inside the coach. To facilitate easy exist of passenger and their immediate rescue during such emergencies, this Emergency Light Unit is developed to provide illumination during failure of all other power supplies inside the coach. These emergency lights are provided inside the conventional and LHB type AC and Non AC coaches and on doorways of these coaches, which would switch 'on' automatically in the event of failure of normal supply system. Hence relliability of Emergency Light Unit is if paramount Importance