Today we are going to demonstrate a very interesting project of a Rain sensor alarm. This is an ideal circuit for those who enjoy electronics as a hobby or those who are studying it. It is simple and beginner-friendly and uses only three components. This circuit is very sensitive to detecting rain therefore it gives accurate results always.
The sensor part can be made with a Veroboard but it can also be made by simply attaching thin metal strips on plastic or wood if you’re not familiar with Veroboard.
Hardware Components
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Input Supply DC | 9V | 1 |
| 2. | Sensor | – | 1 |
| 3. | Buzzer | 9V | 1 |
| 4. | Transistor | BC547B | 1 |
| 5. | Variable Resistor | 300K | 1 |
Circuit Diagram
Working Explanation
The main component of this circuit is a BC547B transistor that is working as a switch in this circuit. The sensor is very sensitive to raindrops. The sensitivity of the circuit is adjustable and can be adjusted by a variable resistor of 300K ohms. When the water droplets fall onto the strips of the sensor it turns the circuit on as water is a great conductor of electricity. Now the voltage will be passed to the transistor and it receives its required 9V. This will activate the transistor which results in activating the buzzer connected to it. The buzzer acts as an alarm in this circuit and it will let the user know about rain.
While making this circuit make sure that the sensor strips should not have a gap of more than 1minimeter to get better performance. The sensor can be made by several techniques depending on your convenience and choice.
Applications and Uses
A rain sensor alarm is a very useful device to alert when it is raining. It can be used in several areas and places where the user wants to be alerted the moment a single raindrop falls.
