GENERAL OVERVIEW
1.1 INTRODUCTION: In an automobile headlight, a 'meeting' beam (dip beam) is provided in addition to the driving beam (high beam) so as to reduce the dazzle for those approaching head-on to the vehicle. The Auto Dipping Device for a head light is intended to automatically change the Headlight Circuit to either driving beam or dip beam given a particular set of road conditions, without the intervention of the driver. The present practice is to operate the dip switch manually. The function of the headlight is to illuminate the road ahead of the automobile so as to reveal objects ahead from a safe distance; at the same time it should cause minimum discomfort and glare for drivers coming from the opposite side. Manual dipping is not being done satisfactorily in India due to a variety of reasons, which includes sheer physical strain involved in operation of the dipper switch hundreds of times every night. (The total for a single night will be 1000 if we consider 8 hours of traveling and one encounter every one-minute and could exceed this number if one travels on roads with dense traffic). The other reason includes a general tendency of paying more attention to steering control at the cost of dipping during a critical vehicle meeting situation especially in the case of heavy loaded vehicles. More reasons are the physiological and psychological state of a driver, which is influenced by a variety of factors like working hours, economic issues and social factors etc. Another major cause is 'ego problem', which makes each one wait till the other person initiates dipping, which may not happen. A frequent cause of accidents at nights is the glare caused by oncoming vehicles which momentarily blinds the driver's vision. It takes three to eight seconds for a person with good eyesight to recover from the glare and during this time the vehicle will have covered a long distance in utter darkness and it will be sheer luck if it