17-05-2014, 03:43 PM
Automatic street lights on & off using light dependent resistor
Automatic street lights .pdf (Size: 1.15 MB / Downloads: 24)
INTRODUCTION
We need to save or conserve energy because most of the energy sources we
depend on, like coal and natural gas can't be replaced. Once we use them up, they're
gone forever. Saving power is very important, instead of using the power in unnecessary
times it should be switched off. In any city “STREET LIGHT” is one of the major power
consuming factors. Most of the time we see street lights are ON even after sunrise thus
wasting lot of energy. Over here we are avoiding the problem by having an automatic
system which turns ON & OFF the street lights at given time or when the ambient light
falls below a specific intensity. Each controller has an LDR which is used to detect the
ambient light. If the ambient light is below a specific value the lights are turned ON.
A light dependent sensors is interfaced to the pic18f452 microcontroller it is used
to track the sun light and when the sensors goes dark the led will be made on and when
the sensor founds light the led will be made OFF.
It clearly demonstrates the working of transistor in saturation region and cut-
off region. The working of relay is also known Microcontroller and the code is written
in c language in MikroC ide, the resulted value can be seen with the help of UART or
LCD display .Automatic Street Light Control System is a simple yet powerful concept,
which uses transistor as a switch. By using this system manual works are 100% removed.
It automatically switches ON lights when the sunlight goes below the visible region
of our eyes. This is done by a sensor called Light Dependent Resistor (LDR) which
senses the light actually like our eyes. It automatically switches OFF lights whenever
the sunlight comes, visible to our eyes.
LIGHT DEPENDENT RESISTOR
LDRs or Light Dependent Resistors are very useful especially in light/dark sensor
circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000000
ohms, but when they are illuminated with light resistance drops dramatically. Electronic
onto sensors are the devices that alter their electrical characteristics, in the presences of
visible or invisible light. The best-known devices of this type are the light dependent
resistor (LDR), the photo diode and the phototransistors.
PIC18f452 MICROCONTROLLER
Microchip manufacture a series of microcontrollers called PIC. (Peripheral
interface controller). There are many different flavours available, some basic low
memory types, going right up through to ones that have Analogue - To - Digital
converters and even PWM built in. A PIC microcontroller is a processor with built
in memory and RAM and you can use it to control your projects (or build projects
around it). So it saves you building a circuit that has separate external RAM, ROM and
peripheralchips.