Vehicle intersection lighting automatic control circuit at night

When cars are driving at night and there are vehicles crossing each other, according to traffic regulations,
the two vehicles should alternately turn on and off the headlights at a specified distance, and
turn off or turn on the wide or low beam lights at the same time to ensure the safe passage of vehicles
. The circuit shown in Figure 13-50 serves this purpose.
    In the picture, ELi and EL2 are the big lights, and SA is the manual
switch .