IntroductionAll fluorescent lamps (FL), including the well known straight lamps and the newly developed compact fluo rescent lamps (CFL), display a negative voltage-current characteristic, requiring a device to limit the lamp cur rent when the FL is connected to a voltage source. Otherwise an ever increasing power dissipation would destroy the lamp. This current limiting device can be a resistor in series with the lamp. However for achiev ing low power dissipation and high efficiency an induc tive ballast is typically used. Whereas pure magnetic (in ductive) ballasts need additional starting elements such as glow switches or transformers, electronic control gear (ECG) incorporates all the equipment necessary for starting and operating a FL. During operation, ECGs generate high frequency voltages, most commonly in the range of 25-50 kHz, compared to conventional ballasts, which operate lamps at 50 or 60 Hz. This dif ference in the frequency of lamp operation is the main reason for nearly all the advantages of ECGs.