In this project, we are demonstrating a circuit of Cold Sensor Switch utilizing LM35 IC and CA3140 ICs. The circuit can be utilized for detecting cold in any area or under any condition. It tends to be utilized with a wide assortment of tasks in which you require to detect temperature reduction or coldness. At the output of the circuit, there is a relay that will get enacted on the required coldness of temperature decline.
You can associate any DC or AC apparatus with the relay switch to actuate it on the required temperature decline. This method is one of the easiest methods for making these types of sensors.
Hardware Components
The following components are required to make Cold Sensor Switch Circuit
| S.no | Components | Value | Qty |
|---|---|---|---|
| 1. | IC | LM35 | 1 |
| 2. | IC | CA3140 | 1 |
| 3. | Diode | 1N4007 | 1 |
| 4. | Resistor | 470Ω | 1 |
| 5. | Relay Switch | – | 1 |
| 6. | Variable Resistor | 10k | 1 |
| 7. | Battery | 5V – 12V | 1 |
CA3140 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of CA3140
LM35 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of LM35
Cold Sensor Switch Circuit
Working Explanation
Under this heading, we are talking about the circuit operation of the cold sensor switch using LM35 and CA3140. This circuit requires a few low-cost components which are easily accessible in the electronics market. The circuit is utilizing two ICs which are LM35 and CA3140. LM35 is an excellent, exact, low current utilization and low-cost temperature sensor IC. Another extraordinary feature of this IC is that it does not require any calibration since it is as of now adjusted by the maker. Another IC utilized in the circuit is a CA3140 which is an op-amp IC. In this circuit, this IC is utilized as a comparator. The required temperature to turn on the transfer can be chosen with the 10k variable resistor.
Applications and Uses
This circuit screens the temperature level in Labs, AC rooms, Cold storage, and so on and gives signals to you whether the low temperature is sustained in the room or not.
