30-07-2014, 01:07 PM
AUTOMATIC STREET LIGHT INTENSITY CONTROLLER
[attachment=66372]
INTRODUCTION
High intensity discharge lamp (HID) presently used for urban street light are based on principle of gas discharge, thus the intensity is not controllable by any voltage reduction method.
By using LED’s, light intensity can be varied thus reducing wastage of power
As the vehicle moves forward, the intensity goes on increasing for few lights ahead, and as it passes away the intensity goes on falling. Thus this way of dynamically changing intensity helps in saving a lot of energy. A programmable microcontroller is engaged to provide different duty cycle for different intensities at different density conditions.
TRANSFORMER:
Transformers convert AC electricity from one voltage to another with a little loss of power. Step-up transformers increase voltage, step-down transformers reduce voltage. Most power supplies use a step-down transformer to reduce the dangerously high voltage to a safer low voltage.
VOLTAGE REGULATOR
Features
• Output Current up to 1A
• Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V
• Thermal Overload Protection
• Short Circuit Protection
• Output Transistor Safe Operating Area Protection
Description
MICRICONTROLLER:
The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional non volatile memory programmer. It is a highly flexible and cost-effective solution to many embedded control applications. The AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset.
Features:
• Compatible
• 256 x 8-bit Internal RAM
• Eight Interrupt Sources
• 32 Programmable I/O Lines
• Low-power Idle and Power-down Modes
Highway model circuit:
• The highway model consists of 14 streetlights and 8 pairs of photodiodes-IR diodes used as sensors, variable resistors and transistors which acts as switch. The IR diodes are placed on one side of the road and photodiodes are placed on the other side of the road, directly facing the IR diodes.
• Consider the case when there is no vehicle on the highway. In this case, the IR radiation emitted from the IR diode directly falls on the photodiode which is exactly opposite to it. This causes the photodiode to fall in conduction state. This implies that photodiode conducts and current passes through it. The current passes through the photodiode and goes through the variable resistor and the base-emitter region of the transistor. This in turn connects the collector of the transistor to the emitter. Emitter
is connected to ground which implies that the collector also goes to the ground. The collector region of the transistor is connected to the port 1 (input port) which in turn goes to ground i.e., logic ZERO. So, to summarize we can say that, when there is no vehicle on the highway, then the inputs to the microcontroller port 1 is ZERO.
CONCLUSION
This project of DENSITY SENSED STREET LIGHT INTENSITY CONTROL TO SAVE ENERGY is a cost effective, practical, ecofriendly and the safest way to save energy. It clearly tackles the two problems that world is facing today, saving of energy and also disposal of incandescent lamps, very efficiently. According to statistical data we can save more that 40 % of electrical energy that is now consumed by the highways. Initial cost and maintenance can be the draw backs of this project. With the advances in technology and good resource planning the cost of the project can be cut down and also with the use of good equipment the maintenance can also be reduced in terms of periodic checks. The LEDs have long life, emit cool light, donor have any toxic material and can be used for fast switching. For these reasons our project presents far more advantages which can over shadow the present limitations. Keeping in view the long term benefits and the initial cost would never be a problem as the investment return time is very less.
[attachment=66372]
INTRODUCTION
High intensity discharge lamp (HID) presently used for urban street light are based on principle of gas discharge, thus the intensity is not controllable by any voltage reduction method.
By using LED’s, light intensity can be varied thus reducing wastage of power
As the vehicle moves forward, the intensity goes on increasing for few lights ahead, and as it passes away the intensity goes on falling. Thus this way of dynamically changing intensity helps in saving a lot of energy. A programmable microcontroller is engaged to provide different duty cycle for different intensities at different density conditions.
TRANSFORMER:
Transformers convert AC electricity from one voltage to another with a little loss of power. Step-up transformers increase voltage, step-down transformers reduce voltage. Most power supplies use a step-down transformer to reduce the dangerously high voltage to a safer low voltage.
VOLTAGE REGULATOR
Features
• Output Current up to 1A
• Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V
• Thermal Overload Protection
• Short Circuit Protection
• Output Transistor Safe Operating Area Protection
Description
MICRICONTROLLER:
The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional non volatile memory programmer. It is a highly flexible and cost-effective solution to many embedded control applications. The AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset.
Features:
• Compatible
• 256 x 8-bit Internal RAM
• Eight Interrupt Sources
• 32 Programmable I/O Lines
• Low-power Idle and Power-down Modes
Highway model circuit:
• The highway model consists of 14 streetlights and 8 pairs of photodiodes-IR diodes used as sensors, variable resistors and transistors which acts as switch. The IR diodes are placed on one side of the road and photodiodes are placed on the other side of the road, directly facing the IR diodes.
• Consider the case when there is no vehicle on the highway. In this case, the IR radiation emitted from the IR diode directly falls on the photodiode which is exactly opposite to it. This causes the photodiode to fall in conduction state. This implies that photodiode conducts and current passes through it. The current passes through the photodiode and goes through the variable resistor and the base-emitter region of the transistor. This in turn connects the collector of the transistor to the emitter. Emitter
is connected to ground which implies that the collector also goes to the ground. The collector region of the transistor is connected to the port 1 (input port) which in turn goes to ground i.e., logic ZERO. So, to summarize we can say that, when there is no vehicle on the highway, then the inputs to the microcontroller port 1 is ZERO.
CONCLUSION
This project of DENSITY SENSED STREET LIGHT INTENSITY CONTROL TO SAVE ENERGY is a cost effective, practical, ecofriendly and the safest way to save energy. It clearly tackles the two problems that world is facing today, saving of energy and also disposal of incandescent lamps, very efficiently. According to statistical data we can save more that 40 % of electrical energy that is now consumed by the highways. Initial cost and maintenance can be the draw backs of this project. With the advances in technology and good resource planning the cost of the project can be cut down and also with the use of good equipment the maintenance can also be reduced in terms of periodic checks. The LEDs have long life, emit cool light, donor have any toxic material and can be used for fast switching. For these reasons our project presents far more advantages which can over shadow the present limitations. Keeping in view the long term benefits and the initial cost would never be a problem as the investment return time is very less.