The article presents a project of an “LED thermometer with a selectable temperature switch”. However, a thermometer is a device that estimates “temperature” or a “temperature gradient”. It is likewise the level of “coldness” or “hotness” of any object. This LED thermometer utilizes a standard accuracy temperature sensor that has a “linear voltage output” depending on the room temperature.
In this tutorial, we are developing a digital thermometer with some selectable temperature switches. Hence this project is easy to make and does not use many components. Since the thermistor of 10K is the primary component of this project.
Hardware Components
The following components are required to make an LED Thermometer Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Thermistor | 10K | 1 |
| 2. | Resistor | 22K, 1K, 15K | 1, 1, 1 |
| 3. | LED | – | 10 |
| 4. | DC Supply | 5V-12V | 1 |
| 5. | Relay | 12V | 1 |
| 6. | Diode | 1N4007 | 1 |
| 7. | Transistor | BC327 | 1 |
| 8. | Variable Resistor | 10K | 1 |
BC327 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of BC327
LED Thermometer Circuit
Working Explanation
Now we will discuss the circuit operation of an “LED thermometer with selectable temperature switches” in detail. However, the circuit can be balanced for any temperature range, a relay is utilized at the output of the circuit that will get initiated on any chosen temperature, the 10K NTC thermistor is utilized to detect the temperature and a 10K variable resistor is utilized to choose the necessary temperature range.
Trying different things with various estimations of thermistors and variable resistors will likewise help in accomplishing the precise required temperature range. The circuit utilizes 10 LEDs to show visual signals of temperature, the point marked IC Connection is the temperature selection point to actuate the relay switch on the necessary temperature, it very well may be associated with any pin of the IC that is associated with the LED. Since the working voltage of the circuit is 5V to 12V.
Applications and Uses
- These thermometers use the extent of physical impacts to quantify temperature.
- Temperature sensors are utilized in a wide assortment of engineering and scientific applications, particularly measurement systems.
