“Mechanization is good, as long as it satisfies the machine particularly clearly,” we’re using a thermistor in our tutorial so that it commences above the prescribed level and stops when the temperature reaches a certain level. It is automatically updated in this operation.
Hardware Component
The following components are required to make Temperature Controlled DC Fan Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | DC Fan (Motor) | – | 1 |
| 2. | Potentiometer | 10k | 1 |
| 3. | NPN Transistor | MJE3055 | 1 |
| 4. | NTC Thermistor | 10k | 1 |
| 5. | Resistor | 4.7k, 47 Ohm | 1 |
| 6. | Op-amp IC | LM741 | 1 |
| 7. | Power supply | 5v | 1 |
| 8. | Breadboard | – | 1 |
| 9. | Connecting wires | – | 1 |
LM741 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of LM741
Temperature-Controlled DC Fan Circuit
Working Explanation
It is focused on the thermistor principle. Throughout this circuit, the potentiometer is joined well together with PIN 3 (Non-Inverting Stimulation Circuit op. 741), and the voltage amplifier circuit PIN 2 (inverting Stimulation Circle) correlates the R2 to RT1 (thermistor). The op amp’s highlighted features are LOW in its resting condition as the non-inverting input voltage is smaller than those of the inverting input that keeps the NPN transistor out.
The transistor is OFF since the voltage on the base is non-applied, and a voltage at the base is essential to perform the transistor NPN. Here we used the MJE3055 NPN transistor, but any high-current transistor, including BD140, may operate here.
The thermistor decreases, and the output of the non-inverse terminals of op-amp may not boost even as temperature increases, and hence the op amplifying output PIN 6 remains HIGH. The transistor remains ON (from when the op-amp output is HIGH, the voltage passes via the input to the output). Now the NPN transistor can be operated by the fan. The fan will effectively cut off when the thermistor returns to its original position.
Applications and Uses
- Laptops and electronics cooling fans.
- The whole machine is used to cool the motor.
