Minor Project

The basic principle behind operation of ANTI THIEF ALARM SYSTEM is conservation of energy and transformation of one form of energy to another form of energy. The law of conservation of energy states that " Energy Can Neither Be Created Nor Destroyed But It Can Be Changer From One Form To Another". In this circuit we have conservation as well as transformation of energy with of help of different type of transducers. A transducer is a special type of device which has the feature of convening one form of energy to another form of energy. Initially the mechanical energy that is pleasure applied on the piezoelectric element is converted into its electrical equivalent due to unique characteristic of the piezoelectric .Then the electrical energy is again convened into sound energy with the help of UM3561 IC which has the special characteristic of converting electrical energy to its sound energy equivalent.

Circuit diagram of Anti thief alarm

Circuit diagram of 9Volt Regulated power supply

In ANTI THIEF ALARM SYSTEM we have conservation as well as transformation of energy with of help of different type of transducers. A TRANSDUCER is a special type of device which has the feature of converting one form of energy to another form of energy. Initially the mechanical energy that is pressure applied on the piezoelectric element is convened into its electrical equivalent due to unique characteristic of the piezoelectric .Then the electrical energy is again converted into sound energy with the help of UM3561 IC which has the special characteristic of converting electrical energy to its sound energy equivalent. This due to unique characteristic of the piezoelectric .Then the electrical energy is again converted into sound energy with the help of UM3561 IC which has the special characteristic of converting electrical energy to its sound energy equivalent. This successive transformation of energy takes place due to special type of transducers i.e.UM3561 (electrical to sound) and piezoelectric element (mechanical to electrical energy).

This circuit work on 5-12V DC supply but in this our circuit work with 9V regulated power supply. In this regulator circuit there is a 909 step down transformer which is used to step down 220V AC supply into 9V AC after this there are four 1N4007 diodes which work up to 1000V these diodes converts AC to DC then there are two electrolytic 1000uf 25V capacitors which is used to smooth the DC because capacitor can pass AC and block DC then there is a regulator IC 7809 which give 9V DC supply.

Assemble the circuit on a general purpose PCB and enclose in a suitable house made by thermacol and card board. Fix the piezoelectric element under the door mat and place the speaker in a central room inside the house using long wires. The circuit works off 5-l2V DC. This circuit works on 9V DC supply using 9V regulated power supply. The siren time can be adjusted through VR1 by changing the R-C time constant of the timer.

This project is 100% working

Click Here Download Project Report