الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
In most areas of domestic, residential, commercial and industrial application of lighting systems fluorescent tube fixtures are extensively made-use-of. This is due to the simple fact that they consume less active power and exhibit a more prolonged operating lifetime than their counterpart the incandescent lamp, also known as the filament lamps.The presumed superior performance of the fluorescent tubes are sometimes outweighed by the mandatory presence of the magnetic ballast usually referred to as the magnetic ballast and the starter as an auxiliary device necessary to ignite the arc and cause the start and operation of the fluorescent tube. These added components will augment the initial cost of the fluorescent fixture and among other defects, to be stated and discussed at a later stage, may impair the overall lighting system credentials [1- 3].The recent developments in the technology of manufacturing power electronic devices has brought-in a direct replacement to the combination of the magnetic ballast/starter known in the literature as the electronic ballast on one hand and to the compact fluorescent lamp as a direct replacement to the filament lamp on the other hand . These alternatives have presumably offered solutions to some of the problems associated with the magnetic ballast performance and the filament lamp inefficiency [4], but with the inevitable outcome of introducing new problems in the course of their operation [5-7]. In the early 1990’s, the then newly introduced devices, namely the electronic ballasts and the compact fluorescent lamps, appeared to be the ultimate solution to the lighting problems as a solution to both the magnetic ballasts and to the incandescent lamps. Now, after two decades of operation with the electronically-based ballasts, and considering their ever-growing utilization, it is an appropriate time to re-evaluate their impact on the field of illumination and on other relevant fields.The overall performance of these devices must be thoroughly tested and revised and accordingly, their long term benefits and drawbacks can be arbitrarily assessed against the magnetic ballasts performance.It is the purpose of this thesis to carry out a practical investigation to the electrical and optical performances of selected sample of the magnetic and electronic devices in question commercially available on the Egyptian market.An overview to the principle of operation of the magnetic ballasts is presented with a reference to their basic types and characteristics altogether with a review to their relative properties. A list of related terminologies and definitions is presented in Chapter II.A historic and practical survey to the various types of electronic ballasts is included in Chapter III with a particular reference to the development in their principle of operation and to their operating circuits. New designs were introduced to the electronic ballasts circuits for the purpose of improving their power factor and to provide them with extra forms of control such as dimming property, remote operation, etc…. .