Abstract: The electronic device described in the present patent application applies to the accessories used to automate the main beams that use sensors to detect the light coming from the vehicles met along roads. The device reduces or even suppresses the undesired effects produced by reflections, onto the surrounding objects, of the lights of the vehicle on which it is mounted, thus avoiding undesired main beam turn-off signals. Said device is particularly convenient to use if mounted after the vehicle is commissioned, being it compatible with wireless transmission systems which make its installation easier.