To stop "jump the gun" runners the top circuit requires each runner to press a button down in starting blocks or else the starting gun (lamp and SPST switch) will not fire.
Bottom is motor driving a belt or rope between two pulleys (lamps) with a flag (ampere meter) to set pace for swimmers or runners so coach does not need stop watch and athletes can see instantly when and where they are not keeping the set pace. Also, this can be set to slow speeds to teach rhythm and relaxation skills.
