A new integrated variable transformer topology for electronic ballasts

The purpose of this work is to present a completely new and different approach to magnetically-controlled electronic ballasts for fluorescent lighting systems, based on an integrated variable transformer. The authors propose an effective way to control the lamp operation, by integrating the magnetic component necessary to control the lamp current into a variable transformer which grants simultaneously output electrical isolation. It is suggested a new variable transformer topology and presented a comprehensive description of its behavior, modeling and characterization. Experimental results validate the model and the adequacy of this new control technique.