Construction Of An Intruder Alarm System

INTRODUCTION
As the world is developing the need for electronics in human endevour is now taking a lager scope. With the inventions of certain electronic gadgets in our society today. Certain activities become easily handed for example; in communication when the telephone plays a path. In places where safety is needed on alarm system will be of much important. The application of electronic in this modern age is simply inexhaustible and this group take more interest in the case of burglary in homes, cars and industry. The selection of a proper alarm is not a simple matter, because the need of each individual home owner or businessman is different like a set of finger prints.
Some factors and questions which must be answered when selecting an alarm system includes:
a) What system needed to be protected?.
b) What type of senior are needed?.
c) The method of transmission needed forth alarm signal.
The purpose of producing the alarm system is to limit the effect of the criminology in the society by informing us that our properties are in danger. All these will bring alarm the way by which criminal break into private properties by scaring them away once the alarm is trigger on. The type of alarm system been built is called INTRUDER ALARM SYSTEM and it is simple but effective alarm circuit which can reset its self after a time that which have been selected. It has normally closed and normally open triggers which make this door as a switch so as to triggers. It on a 555 timer so that alarm will reset itself after a certain amount of time. The time is varied according to the resister and capacitor been used in the circuit. The alarm has a switch, which we can replace with a key switch to make it more secure and we can change the trigger to other top of the door or window sluitchep too. The alarm uses relay, which is connected to a siren (speaker) but it can be replaced with speaker. The circuit is running off 12volts but can be range from 4 – 16volts.