Project on fan controller by sensor and thermistor

Arduino-Based Automatic Temperature Fan Speed Controller
In many small or large industry, you may have seen such a lot of fan that speed is control according to the temperature of the place. Thus, during this article, we have presented a demo of that application. It's assumed that you have an idea of how to read reading from the temperature sensor IC. In industry
temperature range will be more than 100 oC but here we will work on the very low range.
Block diagram of Temperature control FAN

block diagram of temperature control fan using arduino board
Block Diagram
Required Components
Arduino UNO board (buy from here arduino )
Temperature sensor IC LM35( buy from here LM35 sensor )
DC Fan
resistor 1* 1K
16*2 LCD Display
Power supply
Diode(1N4007)
Circuit Diagram
In this application, we use an arduino board to control the speed of the fan and a 16*2 LCD display to display the status of the fan. Here we use a diode in parallel with FAN to prevent it from the damage and a 9V battery to provide power to the fan.

circuit diagram of arduino based temperature control fan
Circuit Diagram
Code
Again like our previous projects, code for this projects is also very simple. Here we use an analogRead() function to get the value of temperature sensor and store that value in the variable.When this value will exceed the min_temp value then the fan will start otherwise its always off. Download the file to get the source code of this projects along with its circuit diagram.
more refrence:http://projectsdunia.blogspot2015/03/arduino-based-automatic-temperature-fan.html