This project proposal describes a rain detector alarm circuit that detects rain and triggers an alarm. The circuit uses a rain sensor that conducts electricity when rain falls on it. This closes a circuit that turns on transistors which power an LED and activate a 555 timer chip. The timer chip produces pulses that drive a buzzer to sound the alarm. The alarm is meant to alert people when it rains so they can take actions like rainwater harvesting or protecting materials from rain. It is a simple, low-cost circuit that can be used for irrigation, home automation, vehicle windshield wipers, and more.

1. TASK Project Proposal
SUBJECT: ECA
SUBMITTED BY: Rizwan Shah
REGISTRATION NO FA20-BSE-167
SUBMITTED TO: Sir Hamza Saleem
DATE OF SUBMISSION: 25-04-2021

2. RAIN DETECTOR ALARAM
INTRODUCTION:
Rain Alarm Project is a simple but very useful project that detects Rain (Rain Water) and
automatically triggers an alarm or buzzer. The main purpose of this project is to prevent the
materials from rain. Using this project we can avoid the mental stress.
Water is a basic need in every one’s life. Saving water and proper usage of water is very
important. Here is an easy project which will give the alarm when there is rain, so that we can
make some actions for rain water harvesting and also save the rain water for using it later. With
the help of saving this rain water through rain water harvesting, we can increase the levels of
underground water by using underwater recharge technique.
Rain water detector will detect the rain and make an alert; rain water detector is used in the
reliable circuit of rain water detector which can be constructed at low cost irrigation field, home
automation, communication, automobiles etc. Here is the simple and irrigation field, home
automation, communication, automobiles etc.
CIRCUIT DIAGRAM:
WORKING PRINCIPAL:

3. We will see the working of the simple Rain Sensor Alarm Circuit Project. When rain falls on the
sensor, the Aluminum Wires on the Sensor Board will start conducting and close the path
between the supply and base of the transistor Q2.
❖ As a result, the Transistor Q2 will turn ON, which will also turn ON the Transistor Q1.
This will turn ON the Bright RED LED connected to the emitter of the Transistor Q1.
❖ When the transistor Q2 is saturated, the capacitor C1 will be shorted and will make the
transistor Q3 to be turned ON. C1 will get charged by the resistor R4.
❖ When the Transistor Q3 reaches the saturation mode, the Reset Pin of the 555 Timer IC,
which is connected to the emitter of Q3, will be made positive.
❖ The 555 timer is configured in astable Mode. As the Reset pin of the 555 Timer IC is
given positive voltage, it becomes active and we will get a Pulse signal at the output pin 3
of the 555 Timer IC. This will turn ON the buzzer and the alarm is activated.
❖ If you are using a speaker, Capacitor C4, which is connected in between the Pin 3 of 555
timer and the speaker, will block the DC signal and allows only the variations in the
signal which makes the speaker to make sound. The diode D1 will not allow any reverse
current from the timer.
❖ Because of the resistor R4 and capacitor C1, when the capacitor is completely charged,
the transistor Q3 will get in to cut – off mode after sometime.
❖ As a result, the Reset pin of the 555 Timer IC will not receive any positive voltage and
the speaker will stop making sound. The time for 555 Timer to make speaker sound
depends on the values of C1 and R4.
❖ When there is no rain, the aluminum wire on the sensor will not conduct as they do not
have any conduction path (open circuit). As a result, the sensor cannot trigger the 555
Timer IC and there will be no alarm.
Proteus Circuit:
When No Rain is Detected:

4. In the below circuit I used bush button instead of rain sensor when push button is in open
condition its means that the rain senor isn’t detected rain and there will be no alarm and LED
will not glow.
When Rain is Detected:
In the above the push button is in closed condition means that the rain sensor detected rain as
a result the circuit is energized and the LED start to glow and buzzer start ringing.

5. BLOCK DIAGRAM:
RAIN WATER RAIN SENSOR AMPLIFIER
TIMER IC
OUTPUT AS
SOUND AND
LIGHT

6. APPLICATION:
• In the irrigation, it will detect the rain and immediately alert the farmer.
• In automobiles, when the rain detector detects the rain it will immediately active the
wipers and inform the driver.
• In communications, it will boost the power of the antenna and increase the signal strength
to send or receive the signals.
• In normal house hold.
• This can also be used if there is a chemical rain also.
• To conserve water
• To prevent disease damage and nutrients loss