【正文】 batteries are also popular because they are maintenance free and they last a lot longer. VI. CONCLUSION This paper has studied about various advancements in the field of solar based LED street light. the use of solar tracking system has greatly increased the system and has helped to increase its overall output. Whereas the use of charge control circuit in the solar based LED street light has not only helped in saving the battery power but also in preventing the battery from getting deep discharged, overcharged, thereby conserving a lot of energy. R EFERENCES [1] Design and Construction of an Automatic SolarTracking System Md. Tanvir Arafat Khan, . ShahrearTanzil, RifatRahman, S M ShafiulAlam*, Member, IEEE Department of Electrical and Electronic Engineering, [2] M. A. Green, “Clean Electricity from Photovoltaics,” Ed. Mary and R. Hill, Series on Photoconversion of Solar Energy, V. 1,Imperial College Press, UK. [3] . Panait and T Tudorache, “A Simple Neural Network SolarTracker for Optimizing Conversion Efficiency in OffGrid Solar Generator”Intl. Conf. on Renewable Energy and Power quality, , March, 2021. [4] Piao, . Park, J. M. Kim, J. H. Cho, G. B. Baek, H. L, “ A study on the tracking photovoltaic system by program type,” Intl. Conf. on Electrical Machines and Systems, vol. 2, pp. 971973, Sept. 2729, 2021. [5] C. Hua and C. Shen, “Comparative study of peak power tracking techniques for solar storage system,?? Applied Power Electronics Conference and Exposition, vol. 2, pp. 679685, Feb. 1519, 1998. [6] A. K. Saxena and V. Dutta, “A versatile microprocessor based controller for solar tracking,?? Photovoltaic Specialists Conference, vol. 2, pp. 11051109, 1990. [7] B. Koyuncu and K. Balasubramanian, “A microprocessor controlled automatic sun tracker,?? IEEE Transactions on Consumer Electronics,vol. 37, no. 4, pp. 913917, 1991. [8] Design and Construction of an Automatic SolarTracking System Md. Tanvir Arafat Khan, . ShahrearTanzil, RifatRahman, S M ShafiulAlam*, Member, IEEE 太陽能 LED 路燈 摘要： 我們是在節(jié)約能源可再生資源和利用已經(jīng)成為一種必然的時間。t overcharged. Connecting a solar panel to a battery without a regulator seriously risks damagingthe battery and potentially causing a safety concern. Charge controllers (or often called charge regulator) are rated based on the amount of amperage they can process from a solar array. If a controller is rated at 20 amps it means that you can connect up to 20 amps of solar panel output current to this one controller. The most advanced charge controllers utilize a charging principal referred to as Pulse WidthModulation (PWM) which insures the most efficient battery charging and extends the life of the battery. Even more advanced controllers also include Maximum Power Point Tracking (MPPT) which maximizes the amount of current going into the battery from the solar array by lowering the panel39。)/176。 approximately ((180176。 of rotationis not required to be done by the solar tracker. Half stepping of stepper motor is considered which gives 176。 in 15 minutes. Delay for minutes and 15 minutes are required. These delays are mentioned as short delay and moderate delay respectively. The lasthour before sunset will provide additional energy to rotate thepanel in the initial position and so the tracker no more rotatesto the west rather it will rotate reversely. As 2 hours in day time are not considered for tracking, (2?15176。/24=) 15176。 motor rotates one step. 3) Timers: Builtin timer of ATMEGA32 is utilized to create delay. The Earth rotates on its own axis, with respectto the sun 360176。 A bination of different light color changing, the sequential control circuit, can achieve more dynamic change of rich and colorful effect. LED has been widely applied in all kinds of lighting equipment, such as a batterypowered flashlight, mini voice control lamp, security lighting, outdoor and indoor stair floodlight roads and buildings and tag continuous lighting. The emergence of white LED is LED from the identification to the illumination function across a substantive step. White LED closest to the sun, more can well reflect the reality of the irradiation object color, so from a technical perspective, white LED is undoubtedly the most cuttingedge LED technology. White LED has began to enter some application field, emergency lights, flashlights, flash and other products appeared, but because the price is very expensive, so hard to popularize. White LED popularization is the premise of price decline, and prices must be formed in the white leds is possible after a certain market scale, integration of the two end depends on technology progress. IV. MICROCONTROLLER The ATMEGA32 microcontroller has been used in the prototype. Microcontroller is the heart of overall microcontroller requires a 5 volt regulated voltage supply. ?7805? voltage regulator is used to providefixed 5 volts supply to the microcontroller .ATMEGA32 has some f