Theft preventer alarm 

This circuit utilising a 555 timer IC can be used as an alarm system to prevent the theft of your luggage, burglars breaking into your house etc. The alarms goes ON when a thin wire, usually as thin as a hair is broken.
The circuit is straightforward. It uses a 555 IC wired as an astable multivibrator to produce a tone of frequency of about 1kHz which gives out a shrill noise to scare away the burglar.
The wire used to set off the alarm can be made of a thin copper wire like SWG 36 or higher.
You can even use single strands of copper form a power cable. The circuit operates on a wide range of voltages from 5V to 15V.
The speaker and the circuit could be housed inside a tin can with holes drilled on the speaker side for the sound to come out.

 

Component List :-

1) 9 Volt Power Source

2) Speaker

3) IC NE555

4) Resistance 68K ohms, 10K ohms,1K ohms

5) Capacitor 0.01 Mfd -2pieces

6)  Capacitor 1Mfd/15V