Theft Preventer Alarm

Hi there, this is my second post for today. So before i start posting, I like to ask you, how much stuff have you loss these days? As I am sick of loosing my instant noodle from my locker, i try to fine out a solution from the internet and here it is, I found out how to make a Theft Preventer Alarm. The circuit is very simple like as shown below. This is a very simple circuit using the NE 555 timer IC as an alarm system to prevent the theft of your luggage, burglars breaking into your house, or people start and opening your room door without knocking ( so annoying sometimes). Back to business, this alarm 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 about 1kHz which gives out a shrill noise to scare away the burglar or eventually make him a little bit more panic.

Edited with Adobe PhotoShop CS3

As shown in the part highlighted diagram above, the wire use to set off the alarm can be made of a thin copper wire like SWG 36 or higher or another option is, you can also even use a single strands of copper from a power cable.


Again like previously, this type of circuit operates on a wide range of voltage from 5v to 15v. So using a 9-volt battery would fit just nice.


That is all from my second post, hope you enjoy it and no more people steeling you stuff of just bum into your room without knocking which might be so annoying for college and universities student nowadays. Here again i am Mohamad Fairulnizam and signing off.