PHYSICS PROJECT REPORT

2014-2015

SUBODH PUBLIC SCHOOL

SUBMITTED BY: GUIDED BY:ARK DUTTA MR.HARI OM OJHA

XI-B DEPARTMENT (PHYSICS)

CERTIFICATE OF AUTHENTICITY

This is to certify that ARK DUTTA, a student of class XI has successfully completed the project report on the topic: ‘Rain Water Detector-Alarm Circuit’ under the guidance of Mr. Hari Om Ojha (Subject Teacher).

This project is absolutely genuine and does not indulge in plagiarism of any kind. The references taken in making this project have been declared at the end of this report.

Signature(Subject Teacher) Signature(Examiner)

ACKNOWLEGDEMENT

The project could have never been possible without the support of various sources. It is extremely impossible to thank every individual who has helped me in completing this project. Some people have helped in the basic formularization and there were sources that helped me in giving the ideas a physical form/shape. I am extremely grateful to my teacher, Mr. Hari Om Ojha, for his invaluable guidance in the project right from the beginning. His vital support helped the project to take a logical and suitable shape.

I take this opportunity to thank the School authorities, for extending their full support and cooperation in the project.

Last but not the least; I would like to thank everyone who has offered a helping hand when required.

INTRODUCTION

Water is basic need in every one’s life. Saving 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 and save the rain water. As a result, we can increase the water 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 irrigation field, home automation, communication, automobiles etc.

Here is the simple and reliable circuit of rain water detector which can be constructed at low cost.

If there is no rain, the resistance between the wires will be very high and there will be no conduction between the wires in the sensor. If there is rain, the water drops will fall on the rain sensor which will also decrease the resistance between the wires and wires on the sensor board will conduct and trigger the transistors circuitry. It will make the output pin high and which will make the buzzer to make alarm.

MATERIAL REQUIRED

Connecting WiresPCB BoardResistors 220k Ohms 10k OhmsA Capacitor

0.01 uFTransistors

TL188BC548

Insulating TapesSolder Machine, Solder Wax and FluxA BuzzerAC/DC Adapter(DC: 9volts)

CIRCUIT DIAGRAM

DETAILS OF MATERIAL REQUIRED Connecting wires and a plug - A normal insulated copper

wire able to withstand 230 – 250 v is required.

A circuit board -A normal board of mica facilitated with clips to simplify the connection.

A small box - To place the equipment safely.

A CAPACITOR-The ability of a metal to store electric charges measures the capacitances of a conductor. It provides high impedance to Alternating Current and stores them while all the D.C components are let to pass. There are different types of capacitors –o PARALLEL PLATE CAPACITORo SPHERICAL CAPACITORo CYLINDRICLAL CAPACITOR

Here we use capacitor of 0.01 uF.

A Resistor - A resistor is an electronic components whose resistance value tells us about the opposition it offers to the flow of electric current. Resistance is measured in ohms.

A Transistor - a semiconductor device used to amplify and switch electronic signals and electrical power. It is composed of semiconductor material with at least three terminals for connection to an external circuit.

WORKING

Water is a conductor of electricity. When water is in contact with the probe then there is a flow of current which reaches to the base of Q1. Transistor Q1 is a NPN transistor which conducts. With the conduction of Q1 electron reaches to Q2 which is a PNP transistor .Q2 also conducts and current flows through the speaker. In a speaker there is inductive coil which causes motion in one direction and also produce induce current which is in opposite direction to the flow of current this induce current in the form of pulse flows through a capacitor, resistance and switches off Q1 and relax .this process repeats again and again till probe is in contact with water or we can say there is a oscillation in the circuit thus speaker diaphragm vibrates and gives a tone. Frequency of the circuit depends on the value of Speaker Coil impendence, Capacitor and Resistance Value.

PHOTO GALLERY

APPLICATIONS OF RAIN WATER ALARM

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.

In normal house hold, with the help of rain water detector we can automatically save the rain water. (This can be done only when home automation is done and equipment to save the rain water. In this, rain water detector will detect the rain and helps to switch ON the equipment which will automatically save rain water for different purposes).

This can also be used if there is a chemical rain also. This is very common in industrial areas.

BIBILIOGRAPHY

1) Electronic projects Blog for beginners by A.K Manini 2) H.C VERMA XIIth3) S.L ARORA PHYSICS XIIth4) NCERT based CBSE text for XIIth5) Website: www.Google.com

THANKS TO ALL.