Here is a circuit to control a fan according to the temperature of environment. If the temperature is high, then the fan will automatically turn on and if the temperature is low then the fan will automatically turn off.
The circuit uses following components
1. 9/12 volt power supply
2. LM741 op-amp
3. BC 547 transistor
4. 6.8 k resistor , 10 k resisotor
5. diode
6. fan or motor
The circuit uses following components
1. 9/12 volt power supply
2. LM741 op-amp
3. BC 547 transistor
4. 6.8 k resistor , 10 k resisotor
5. diode
6. fan or motor
