Posted by Circuits Arena on Friday, 12 December 2014
Fan Controller Circuit by IC LM35 is the artlcle explaining Fan Controller Circuit by IC LM35 It is a simple Circuit and operates automatically switch ON and control a speed of a Fan. Fan C...
Fan Controller Circuit by IC LM35
It is a simple Circuit and operates automatically switch ON and control a speed
of a Fan.
Fan Controller Circuit Diagram
- This project uses IC LM35 as a sensor for detecting accurate centigrade temperature.
- The output voltage of this sensor is linearly proportional to the Celsius temperature.
- Sensor use the fact that, the temperature increases and the voltage across a
diode increases at a known rate. Output of IC is 10mv/degree centigrade
for eg if temperature is 45 degree then the output of sensor will be
450mv or 0.45V.
- The output of sensor is applied to a current amplifier circuit and feed to a low power DC motor.
- We have made current amplifier by using a general purpose NPN transistor. I have used BC548 as shown in the circuit diagram.
- If you are using other NPN transistor, then make sure about pin
configuration. Transistor will start conducting when base voltage
reaches to 0.40 V (40 Degree). You will see fan start to rotate and at
0.60V (60 degree) it will be at full speed. At this voltage transistor
is fully conducted means resistance is low.
Parts List of Fan Controller Circuit:
1) IC LM35.
2) Transistor- BC548, BC187 NPN type.
3) DC Motor.
4) Fan Blade.
5) Resistors - 10 ohms , 4.7ohms.
6) Battery.
