Automatic Irrigation System

1. DEPARTMENT OF ELECTRONICS
AND COMMUNICATION

2. SUBMITTED BY
RANJAN KUMAR GUPTA
ECE - 3rd year
1322231055
Submitted To
Department of Electronics
and Communication
Engineering
Feb 2016

3.  Rain alarm is an application which detects the
rain water and blows alarm.
 They are useful devices and play an important
role in various industries such as automobile,
irrigation, and wireless communication.
 Designing a rain alarm system is quite simple
and we have designed here a demo
rain alarm project with the help of 555 Timer IC.

4. Rain alarm is an application which detects the rain
water and blows alarm. They are useful devices
and play an important role in various industries such as
automobile, irrigation, and wireless communication.
Designing a rain alarm system is quite simple and we
have designed here a demo rain alarm project with the
help of 555 Timer IC.
Components
Rain sensor (Either you can purchase or build yourself)
555 Timer IC
NPN Transistor BC547
Resistors (470, 100k and 1k ohm)
Capacitor (10uf)
Buzzer
Battery 9v

5. PIN DIAGRAM

7. The main component of this rain alarm is rain
sensor, I have purchased one, but we can also build
it at home. It’s very easy to create a rain sensor.
Take a sheet of Bakelite or mica, and paste the
aluminum wire on it according to the diagram
shown below. The Gap between the wires should
be around 3-5mm. You can see that whenever the
rain drop would fall on rain sensor, it will short the
point A and B and a voltage would get applied on
the base of Transistor, and it will become ON. We
can also use copper wire for rain sensor but copper
generally reacts to oxygen to form oxide, so it needs
to be cleaned on regular basis.

8. Circuit Diagram and Working Explanation

9. It is a very simple rain alarm circuit which is designed
using mainly a transistor, water sensor and a 555 timer IC.
Whenever there is a rain, rain drops falls on the rain sensor,
and as you can see in the diagram of rain sensor, water on
rain sensor would short the Point A and B. As soon as Point
A and B become short, a positive voltage would get applied
on the base of Transistor Q1, through the resistance R4.
Because of the voltage at the base, transistor becomes ON
(initially it was in OFF state), and current started flowing
form collector to emitter.
Now Reset PIN 4 of the 555 Timer, gets a positive voltage and
555 timer IC becomes ON and Buzzer starts beeping. Here we
should note that initially there was no positive voltage at
Reset PIN 4 of 555 IC, as it was connected to the ground
through resistance R5 (4.7k) and 555 IC only works when
Reset pin gets positive voltage.

10.  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 to the driver.
 In communications, it will boost the
power of the antenna and increase the
signal strength to send or receive the
signals.

11. THANK YOU