الفهرس 
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Abstract
Due to the energy and fossil fuel crisis around the world, oil prices increase due to that the production of electricity depends mainly on fuel including diesel and natural gas. Therefore, the world seeks to reduce the low-efficiency electrical loads, which waste electricity and replace them with loads of high efficiency.
Lighting purposes present about 25% of world electricity consumption therefore, it is necessary to look for a type of lamps that contribute to energy saving. Light Emitting Diode (LED) lamps work to rationalize the consumption of electricity, which reflects the importance of studying and investigation this type of lamps at the moment.
There is a global interest of LED technology. LED lamps manufacturers and academic researchers are doing great efforts to study every side of LED lamps performance.
This thesis investigates the photometric and electrical properties of LED lamps. The effect of temperature on the output light emitted from the LED lamps has been studied and a model of LED lamp is simulated and presented in this thesis. The presented model has been implemented experimentally to investigate the lamp performance.
Experimental results show that the effect of aging test on photometric parameters of LED lamp such as luminous flux, correlated color temperature (CCT), color rendering index (Ra). This study enables to understand and well control the features of the visible light emitted from LED lamps. The value of CCT is an important parameter in many applications such as lighting, videography, photography, publishing, horticulture and manufacturing. It is desirable to achieve a high CRI light in color-critical applications such as neonatal care in hospitals). Experimental results also demonstrate that power factor of LED lamp driver decreases about 26% from its rated value when the lamp is operated in high ambient temperatures.