In this project we will control multiple cooling devices
using temperature sensor. We will control Fan,AC, room
light and other rdevice. We will make real time project.
It can be use anywhere for long time. We will show room
temperature on LCD.Temperature control is a very useful
device for the public palace. BY using this technique it
is possible to control the speed of the fan
automatically. It is possible to convert normal fan into
temperature sensitive fan by adding a temperature
sensitive logic. By using this technique we not only
save the valuable energy but provide a smart automation
logic in electrical systems.
normal temperature controller we get a output for on
and off purpose only but in this project we control the
speed of the fan automatically. In brief firstly we
convert the temperature into small voltage with the help
of lm 35 sensor. LM 35 is temerature sensor convert the
temperature in to small voltage at very accurately.
Output of the temperature sensor is further converted
into digital signal with the help of the ADC. IN this
project we use ADC0809 . ADC 0809 is a 8 bit ADC and
convert the any analogue signal into digital signal in
100 microsecond. To control the ADC we required a clock
pulse, and 4 different signal . All this signal is
provided by the controller. IN this project we use ic
89s51 as a main controller. IC 89s51 sense the output
from the ADC in hex code. This HEX code is further
converted into binary code with the help of program code
inside the controller. IN the output device we use LCD
display . LCD display display the contents of the
display with the help of the ASCII code. ASCII CODE is
a special code for displaying the character in the LCD.
In the controller we convert the binary code in to ASCII
codes with the help of the code conversion program.
Temperature sensor by the lm 35 is now display in the
ASCII code on the LCD display.
In the controller. We take four different output from
the controller. These different output display the
different temperature zone step by step.
If the temperature is in between 25 to 30 then zone one
is on and if the temperature is in between 30 to 35 then
second zone is on. As the temperature increases
different zones are on step by one. As the temperature
zone increase. LCD display a speed 1 or 2,or3 on the
second line of the display.