Publication

Abstract : As years go by, the population increases, correspondingly increasing the energy demand. Given this scenario, it is essential to implement energy efficient technology to meet our energy requirements. Along this line of thought, came about the idea of solar powered LED street lighting system. It is evident from the title, the system is powered by a solar panel. LED lamps have very low energy consumption and high efficiency, thus are used as the lighting source. The output from the solar panel is fed to a charge controller which feeds a lead acid battery. The battery has a monitor circuit to show its current status of available charge. The voltage supplied by the battery needs to be reduced to a value suited to light up an LED array. For this purpose a buck converter is used. In order to complement the energy efficient nature of the system, a dimmer circuit is introduced. This circuit is used to adjust the brightness of the LED array in accordance with the surrounding brightness in real time. This is achieved via PWM technique. PWM pulses are sent to the switch of the buck converter. Based on the width of the pulse received, the buck converter supplies a certain amount of output voltage to the LED array. Thus on varying the width of the pulse supplied, the voltage supplied to the LED array and in turn it's brightness can be controlled, according to the existing brightness outside.