Simplified electronic ballast circuit diagram

In a building, when the full-power continuous operation of fluorescent lamps is not required, the application of dimmable electronic ballasts can further reduce the power consumption in the building and achieve energy saving. Most modern electronic ballast designs and studies recommend the use of resonant converters as power circuits for driving lamps . Figure 1 shows a simplified ballast circuit. The two switches S: and S2 alternately switch in turn to provide a high-frequency (usually within 25 kHz and 100 kHz) rectangular wave AC voltage , which is applied to the loaded resonant circuit. Blocking (breaking) DC (current) capacitors are used to eliminate DC voltage components. The basic concept is to utilize the resonant voltage applied to the resonant capacitor C, in order to initiate the impact of the lamp arc. Because of the high frequency of the excitation voltage, the lamp is actually in a continuous conduction state, so it can provide high-quality lighting without flicker effects.