Warm-Up and Steady-State Control of High-Pressure Sodium Lamps Applied to Public Lighting Systems

This paper presents a warm-up and steady-state control method for a 70 W high-pressure sodium (HPS) lamp fed by electronic ballast, in order to replace the still commonly used electromagnetic ballasts and take better advantage of lamp's useful life and luminous efficacy. Along this work, a reliable electronic ballast topology has been chosen, attending the specified requirements. After, the warm-up and steady-state control algorithms have been developed and a microcontroller has been chosen to perform them. Finally, the circuit has been assembled and experimental results are shown.