New topologies for low-power and low-input-voltage fluorescent lamp ballasts: tapped-inductor-inverters analysis and design criteria

In this paper several new one-switch nonresonant topologies, that can be used in fluorescent lamp ballasts, are presented and analyzed. The proposed topologies include a tapped-inductor in the power topology. They are specially suitable to implement ballasts for low power fluorescent lamps supplied from a low DC input voltage. The design methodology is focused on obtaining constant luminous flux in the lamp, by regulating the power delivered to the lamp against variations in the input voltage and lamp characteristic. Additionally, design criteria to select the right control method and the circuit parameters are provided.