This tutorial will explain how to control a DC Fan speed by using the temperature sensor (Thermistor). When the temperature rises above the set value, the fan switches On. And stops when the temperature returns to the normal condition automatically.
The temperature sensor circuit using a thermistor exploits the property of a sensor to operate the fan or any other device. This circuit also controls the temperature of any device according to the requirement of an industry. The main idea of a temperature sensor circuit is to control the speed of a fan by heating a thermistor. And the speed of a fan depends upon the temperature of any device like a PC, Laptop, etc
Hardware Required
The following components are required to make DC Fan Speed Control
| S.No | Components | Value | QTY |
|---|---|---|---|
| 1 | MOSFET | IRFZ44N | 1 |
| 2 | Thermistor | 10K | 1 |
| 3 | DC Fan | 12v | 1 |
| 4 | Breadboard | – | 1 |
| 5 | Battery | 12V | 1 |
| 6 | Resistor | 2.2K | 1 |
IRF544N Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of IRF544N MOSFET
Circuit Diagram
Working Explanation
The basic working principle of a fan control temperature depends on the working principle of a thermistor. A thermistor is a device that changes its resistance as the temperature changes. The NTC-type thermistor is used in the circuit whose resistance decreases with an increase in temperature. The circuit uses a voltage comparator which compares the voltage between two inputs that are inverting and non-inverting terminals.
The output of a voltage comparator is responsible for the speed of a fan. Whenever the temperature of a surrounding increases it results in an increase in a temperature of a thermistor. This causes the resistance of a thermistor to decrease. As a result, the output voltage increases which increases the speed of a fan.
Application
- It monitors the environment for larger periods of time.
- The circuit prevents the waste of energy if the temperature is not too hot.
- A Temperature sensor helps people who are disabled to control the speed of a fan automatically.
