Introduction
When it comes to keeping our food fresh and safe, a reliable fridge alarm circuit is a must-have. So, in today’s tutorial, we have decided to make a simple fridge alarm circuit. With this innovative circuit, you’ll never have to worry about spoiled food again. This circuit can be helpful in preventing food spoilage and ensuring safe storage conditions in a refrigerator or freezer.
This fridge alarm circuit requires very few electronic components and is easy to understand. So, let’s get into it!
Hardware Required
You will require the following hardware for the Fridge Alarm Circuit
| S no | Components | Value | Qty |
|---|---|---|---|
| 1 | IC | IC 1 = CL7611 IC 2 = 8211 | 1, 1 |
| 2 | R1, R2, R3, R4, R5, R6, R7, R8 | 4.7MΩ, 2.2M, 56k, 12k, 10k, 270, 390 | 2, 1, 1, 1, 1, 1, 1 |
| 3 | Variable Resistor | – | 1 |
| 4 | Thermistor | GL16 | 1 |
| 5 | Transistor | 2TX300 | 1 |
| 6 | LED | RED, Green | 1, 1 |
| 7 | Switch | – | 1 |
| 8 | Battery | – | 1 |
Steps to make the Fridge Alarm Circuit
You need to follow the given circuit diagram and connections to make the fridge alarm circuit.
Circuit Diagram
Circuit Connections
- Verify that the circuit is properly assembled and all components are in the correct location.
- Check the battery status by observing the LED2, it should be ON when the battery is good and OFF when the battery is low.
- Place the thermistor in a cold environment and measure the resistance with a multimeter. Record the value.
- Heat the thermistor and measure the resistance again. Record the value. The resistance should decrease as the temperature increases.
- Observe the LED1, it should be OFF when the thermistor is in a cold environment and ON when the thermistor is heated above 5°C.
- Repeat steps 3 to 5 with different temperatures and verify that the LED1 glows at the correct temperature.
- Check the alarm output and ensure that it is working properly.
- Connect the power supply to the circuit, and check the functioning of the LED1 LED2 IC1, and IC2.
- Finally, test the circuit with a range of temperatures and check the function of LED1 and the Alarm.
Working Explanation
The TH1 thermistor is used as the temperature sensor in this fridge alarm circuit. The thermistor has a variable resistance that changes depending on the temperature of its environment. In addition, the CL7611 IC1 is included with the thermistor in order to complete the process of developing the system as a whole. We have used IC2 to show the state of the battery. Once the temperature rises over 5 degrees Celsius, the LED1 which is a part of the circuit, will begin to glow.
Final Words
Because of this circuit, you will never have to be concerned about the safety of your food again. We hope that it will be easier for you to make this circuit. For any queries, feel free to ask in the comment section.
