Working principal along with circuit diagram.

ABSTRACT
This research focuses on detection of unauthorized access to residential and commercial buildings when
the residents are far away from the access gate of the house. The system is a simple and reliable touch
activated security system and uses sensor technology to revolutionize the standards of living. The system
provides a best solution to most of the problems faced by house owners in their daily life. Due to its
simple electronic components nature, it is more adaptable and cost-effective. The system is divided into
three units; the power supply unit which employs the use of both DC battery and mains supply to ensure
constant power supply to the circuit, the trigger unit which is responsible for activating the alarm unit
and designed to have much time and period and moderate sensitivity in order to reduce the rate of false
alarm, and the alarm amplitude unit which main function is to produce amplitude alarm sound when
triggered by the trigger unit with the aim of producing a large audible sound that can alert the entire
neighborhood or scare an intruder away. The design of the system was achieved by considering some
factors such as economy, availability of components and research materials, efficiency, compatibility and
portability and also durability in the design process. The performance of the system after test met design
specifications. This system works on the principle of touch sensor. The general operation of the system
and performance is dependent on the presence of an intruder entering through the door and touching any
part of the door. The overall system was constructed and tested and it work perfectly.