27-01-2012, 04:18 PM
solar tracking system
[attachment=16733]
INTRODUCTION
Since the dawn of time man has worshipped the power of the sun & has been in awe of its power to light the planet & give heat to the Earth. Many of the early civilizations revered deities who were Sun gods; the Egyptians had Ra who sailed in his solar baroque across the sky, the Greeks had Helios & Apollo, the Aztecs had Huitzilopochtli, & the Assyrians had Tammuz. The sun gods were generally male & represented the energies of the daytime, of power, light & radiance, whereas female goddesses more generally were linked to lunar, night time energies of reflection, depth & feeling.
In modern times, we are able to view the sun in a more scientific, rational way, but are still painfully aware as to how important it’s light & power is to our everyday lives – if the sun didn’t rise one morning, life as we know it would soon end. So how can we harness the awesome power of the sun to our advantage in our everyday lives?
PROJECT DESCRIPTION
The “Solar tracking system” is micro-controller based system which uses LDR sensors to track the position of sun & stepper motor to rotate the solar panel from east to west. There is also another intensity sensor circuit used to detect the sufficient radiant energy of sun rays to detect sun set or cloudy environment. After detecting sun set solar panel is moved towards extreme east side & switch to low power shut down mode until next sun rise. In cloudy environment micro-controller stops rotating solar panel to save the power.
Solar Panel
This block is very important because it provide power to whole system. The solar panel receives energy from sun & converts it into electrical energy which is stored in storage battery.
Storage Battery
The battery is a device which stores the electrical energy supplied by panel & provides power for the whole system. It also provides supply to the application devices such as CFL lights, fan, etc.
The battery being used is lead acid battery. It is 12V, 7.2AH battery.
LDR (Light Dependant Resistor)
LDR is light sensor. Its resistance changes with light intensity falling on it. Three LDR sensors are used in the tracker circuit to track the position of sun. Each LDR represents the position of sun with respect Solar panel (i.e. East, Centre & West). One LDR is used to detect the intensity of sun light.
Tracker Circuit
The tracker circuit converts the resistance of LDR to voltage signal by voltage divider principal. The LM339 comparator compares the voltage signal from three LDR's. It outputs the position signal (east, centre, & west) to Micro-controller.
Microcontroller
The micro-controller used is “AT89S52” from “ATMEL”. The AT89S52 is a low-power, low cost CMOS 8-bit micro-controller with 8K bytes of in-system programmable Flash memory. It is based on standard “Intel 8051” architecture & its instruction sets.
STEPPER MOTOR
A stepper motor (or step motor) is a brushless, synchronous electric motor that can divide a full rotation into a large number of steps. The motor's position can be controlled precisely, without any feedback mechanism (see Open-loop controller). Stepper motors are similar to switched reluctance motors (which are very large stepping motors with a reduced pole count, & generally are closed-loop commutated.)
Fundamentals of Operation
Stepper motors operate differently from DC brush motors, which rotate when voltage is applied to their terminals. Stepper motors, on the other hand, effectively have multiple "toothed" electromagnets arranged around a central gear-shaped piece of iron. An external control circuit, such as a microcontroller, energizes the electromagnets. To make the motor shaft turn, first one electromagnet is given power, which makes the gear's teeth magnetically attracted to the electromagnet's teeth. When the gear's teeth are thus aligned to the first electromagnet, they are slightly offset from the next electromagnet. So when the next electromagnet is turned on & the first is turned off, the gear rotates slightly to align with the next one & from there the process is repeated. Each of those slight rotations is called a "step" with an integer number of steps making a full rotation. In that way, the motor can be turned by a precise angle.
[attachment=16733]
INTRODUCTION
Since the dawn of time man has worshipped the power of the sun & has been in awe of its power to light the planet & give heat to the Earth. Many of the early civilizations revered deities who were Sun gods; the Egyptians had Ra who sailed in his solar baroque across the sky, the Greeks had Helios & Apollo, the Aztecs had Huitzilopochtli, & the Assyrians had Tammuz. The sun gods were generally male & represented the energies of the daytime, of power, light & radiance, whereas female goddesses more generally were linked to lunar, night time energies of reflection, depth & feeling.
In modern times, we are able to view the sun in a more scientific, rational way, but are still painfully aware as to how important it’s light & power is to our everyday lives – if the sun didn’t rise one morning, life as we know it would soon end. So how can we harness the awesome power of the sun to our advantage in our everyday lives?
PROJECT DESCRIPTION
The “Solar tracking system” is micro-controller based system which uses LDR sensors to track the position of sun & stepper motor to rotate the solar panel from east to west. There is also another intensity sensor circuit used to detect the sufficient radiant energy of sun rays to detect sun set or cloudy environment. After detecting sun set solar panel is moved towards extreme east side & switch to low power shut down mode until next sun rise. In cloudy environment micro-controller stops rotating solar panel to save the power.
Solar Panel
This block is very important because it provide power to whole system. The solar panel receives energy from sun & converts it into electrical energy which is stored in storage battery.
Storage Battery
The battery is a device which stores the electrical energy supplied by panel & provides power for the whole system. It also provides supply to the application devices such as CFL lights, fan, etc.
The battery being used is lead acid battery. It is 12V, 7.2AH battery.
LDR (Light Dependant Resistor)
LDR is light sensor. Its resistance changes with light intensity falling on it. Three LDR sensors are used in the tracker circuit to track the position of sun. Each LDR represents the position of sun with respect Solar panel (i.e. East, Centre & West). One LDR is used to detect the intensity of sun light.
Tracker Circuit
The tracker circuit converts the resistance of LDR to voltage signal by voltage divider principal. The LM339 comparator compares the voltage signal from three LDR's. It outputs the position signal (east, centre, & west) to Micro-controller.
Microcontroller
The micro-controller used is “AT89S52” from “ATMEL”. The AT89S52 is a low-power, low cost CMOS 8-bit micro-controller with 8K bytes of in-system programmable Flash memory. It is based on standard “Intel 8051” architecture & its instruction sets.
STEPPER MOTOR
A stepper motor (or step motor) is a brushless, synchronous electric motor that can divide a full rotation into a large number of steps. The motor's position can be controlled precisely, without any feedback mechanism (see Open-loop controller). Stepper motors are similar to switched reluctance motors (which are very large stepping motors with a reduced pole count, & generally are closed-loop commutated.)
Fundamentals of Operation
Stepper motors operate differently from DC brush motors, which rotate when voltage is applied to their terminals. Stepper motors, on the other hand, effectively have multiple "toothed" electromagnets arranged around a central gear-shaped piece of iron. An external control circuit, such as a microcontroller, energizes the electromagnets. To make the motor shaft turn, first one electromagnet is given power, which makes the gear's teeth magnetically attracted to the electromagnet's teeth. When the gear's teeth are thus aligned to the first electromagnet, they are slightly offset from the next electromagnet. So when the next electromagnet is turned on & the first is turned off, the gear rotates slightly to align with the next one & from there the process is repeated. Each of those slight rotations is called a "step" with an integer number of steps making a full rotation. In that way, the motor can be turned by a precise angle.
