A ballast is a device used in fluorescent lamps to limit current and generate instantaneous high voltage. It is made by wrapping enameled wire around an iron core made of silicon steel. This coil with an iron core, when turned on/off in an instant, will self induce high voltage and apply it to the electrodes (filaments) at both ends of the fluorescent lamp tube. This action is carried out alternately. When the starter (jump bubble) is closed, the filament of the lamp tube heats up by limiting the current through the ballast; When the starter opens, the ballast will self induce high voltage to be applied to the filaments at both ends of the lamp tube. The filaments emit electrons to bombard the fluorescent powder on the tube wall, emitting light. The starter will be turned on and off several times, and this action will be repeated several times to open the lamp tube. When the lamp tube emits light normally, the internal resistance decreases, and the starter remains in an open circuit state. This way, the current flows stably through the lamp tube and ballast, causing the lamp tube to emit light normally. Due to the constant current passing through the ballast during the operation of the fluorescent lamp, it is prone to vibration and heat generation. Therefore, fluorescent lamps with a ballast, especially when the quality of the ballast is poor, will produce a loud noise, which can be easily burned out over time