
28-1
28.1 Introduction
For decades, improvement in energy eciency has been the main focus in many energy-conversion
applications including lighting. e continuous increase in luminous ecacy of discharge lamps such
as the introduction of T5 uorescent lamps and the arrival of new high-brightness light emitting diodes
(LEDs) marked signicant progresses in light sources. e introduction of electronic ballasts and new
low-loss magnetic ballasts has resulted in the progressive elimination of poor-quality ballasts. e rst
decade of the twenty-rst century is the period during which the electronic ballast technology reached
maturity [1]. e proposa ...