Electronic ballast with automatic luminous variation and presence detection using microcontroller and self-oscillating command

This paper proposes a self-oscillating electronic ballast illumination system controlled by a low cost microcontroller. The microcontroller is used to detect presence and to measure the level of illumination in the environment. The dimming feature is achieved by displacing the operating frequency away from the system´s resonant frequency, which is done by varying a resistance in the gate driver circuit. The paper includes an analysis of the proposed illumination system and its design. Experimental results are included to demonstrate its feasibility.