Rain Detector Circuit for Rain Alarm Projects

Here is the simple project to detect rain instantly. Detect it accurately and quickly using this rain detector circuit. This circuit is very useful to close your window doors and can manage your outside setting before heavy rain. This low cost circuit consumes only less power. Initially it consumes no current when the sensor is dry. Same circuit can be used for different applications such as tank overflow indicator and water level indicator circuit. This DIY electronic project rain alarm circuit will give you an indication of rain with the help of an LED. This circuit can also be connected to a buzzer to sound an alarm. Detect rain and save some water or use it for different applications in different fields such as home automation, automobiles and irrigation field. 

Rain Detector Block Diagram:

Block Description:

Rain Detecting Window: Place the rain sensor according to your application. Rain sensor will detect the rain and complete the circuit.

Rain Sensing Circuit: This simple low cost circuit contains only one BC 547 transistor and two resistors R1 (100ohm) and R2 (1K).

Connector: Output (Vcc, Out, Gnd) from the circuit can be taken through the connector.   

Electronic Components & Module Requirement:

Resistors:

• 1K Resistor : 1 (R2)
• 100 Ohm Resistor : 1 (R1)

Semiconductor:

• BC547 Transistor : 1 (T1)

Miscellaneous:

• Rain Detector PCB : 1
• 3 Pin RMC Cable : 1
• 2 Pin RMC Cable : 1

Circuit Design of Rain Detector:

BC547 transistor is the main component in this circuit. Circuit completes when rain make the sensor wet. If there is no rain there will be no conduction between the wires in the sensor. So the circuit will not be active. If the sensor wires start conduction due to rain droplets, circuit gets activated. As a result transistor BC547 starts switching and will drive an LED to show the status of rain. 5V digital output from the circuit can be used to drive other systems.

PCB

Use the PCB designs provided below to make the circuit and sensor. 

Applications of Rain Detector:

• Can be used in agricultural fields to detect rain and stop irrigation immediately.
• Home automation applications such as closing the windows and doors when raining outside.
• In automobiles it can be used to detect rain and start the wiper automatically.
• Can be used to make rain alarm projects.

​This low cost simple circuit can be easily assembled to make a rain detector for different applications in different fields.

Output expectation:

• 5V Input Voltage
• Rain Detecting as Digital Input
• 5V Digital Output