The driver has the function of overheating protection, but the heat dissipation performance of the bulb material cannot meet the requirements. The driver's overheating protection function will flicker and disappear when it starts to work. A two-stage scheme (AC/DC, DC/DC) is used. The first scheme is "increase output electrolytic capacitor". In theory, the scheme can use electrolytic capacitors to absorb part of the AC ripple, but practical experience tells us that if the ripple is controlled within a certain range (10%), it is difficult to further reduce it unless the electrolytic capacitors are added.