Presented By-
P.Sindhuri
B.T.Vishnu Vihar
M.Vani Divyatha
M.Tejeswar

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ABSTRACT
Nowadays, there are a lot of criminal incidents such as terrorist attacks in hotels & malls. This device helps in detecting metallic objects residing in body. The device is called metal detector. This project is developed to detect lost metals like iron, nails, keys and coins .The first step is to design the control circuit to detect different electrical pulse wave which has a different frequency. It is based on electromagnetic field produced by coil entwined at metal substance.
OBJECTIVES OF THE PROJECT
To study how to develop a system of metal detector
To design a device which can use to detect any changing frequency & pulses and output comes as alarm by speaker
To detect metal substance by using a simple circuit
To know and familiarize the electronic components in terms of function, operation and the characteristic.
WHAT IS METAL DETECTOR ?
A metal detector is simple electronic circuit
used to detect & locate metallic objects
above and below the surfaces
HISTORY
The German physicist Heinrich Wilhelm Dove invented the induction balance system, which was incorporated into metal detectors a hundred years later.
The modern development of the metal detector began in the 1930s, Gerhard Fisher design a machine which would detect metal using a search coil resonating at a radio frequency, he was granted the first patent for a metal detector.
The first industrial metal detectors were developed in the 1960s and were used
extensively for mining and other industrial applications.
INTRODUCTION
METAL DETECTOR STYLES
Metal detectors come in several physical styles "beachcomber," hand-held, and mounted styles can all be effective for their intended use.
Hand-held detectors are smaller and less obtrusive than beachcomber detectors. They are also usually "powerful and sensitive enough to detect all concealed metal weapons, including the smallest knives and guns".
COMPONENTS USED
Transistors -BC547
Diodes -IN4148
Resistors
Capacitors
LED-5mm red
Inductor coil
Buzzer -27mm C.Tone
Battery -9v
Metal detector comprises of three modules
CIRCUIT WORKING
HEART OF THE CIRCUIT-COLPITTS OSCILLATOR
Positive feedback
Voltage divider
Frequency is determined by the inductor and the two capacitors
Metal detector comprises of three modules
a. Oscillating circuit
b. Regulator circuit
c. Indicating circuit
a. Oscillating circuit consists of
1.a first transistor;
2.a second transistor;
3.adjustable resistor coupled to the emitter of the first transistor; and
4.inductor coupled to the base of the second transistor to control the conductive state.
b. Regulating circuit consists of
1.Charging circuit
2.Discharging circuit
3.Regulating transistor
c. Indicating circuit consists of
1.Diode
2.LED
3.Buzzer
PROJECT APPLICATIONS
Coin shooting
Prospecting
Relic hunting
Treasure hunting
Beach combing
REAL-TIME APPLICATIONS
Airport security
Building security
Event security
Item recovery
Archaeological exploration
Geological research
ADVANTAGES
In Schools: The metal detectors in schools are used to reduce any possible risk of violence by right and prompt signals such as beeps and alarms when the detectors find person carrying destructive weapons like knives, guns, bomb etc.
IN INDUSTRIES: Industrial metal detectors are used in the pharmaceutical, food, beverage, textile, garment, plastics, chemicals, lumber, and packaging industries.
DISADVANTAGES
False Reading
Constitutional Rights
Medical Interference
FUTURE SCOPE
MODIFICATIONS IN METAL DETECTOR HELPS TO DISTINGUISH DIFFERENT METALS LIKE FERROUS AND NON FERROUS METALS (GOLD,SILVER ETC..,) AND ALSO HOW MUCH DISTANCE IS THAT METAL FROM COIL
CONCLUSION
Generally, this project become as a role that can give a contribution for all people with one system which is effective and accomplished to handle stolen, robbery and used for finding something that were lost. This is because, this project was build using simple electronic circuit and not too big also having a high performance to protect people asset from stolen and helps to find lost objects.