Introduction to Electrical Seminar Topic on Security Alarm Systems:

Providing security to various organizations is one growing challenges in today’s growing world. There are various methods for providing security like video camera monitoring method and object detection by using sensor method. In this paper we will propose a method which consists of transmitter and a receiver which uses ultrasonic signals for detection of objects using ultrasonic signals. In this paper we will see how the circuit is designed and the how the ultrasonic signals detect the objects and based on the detection alarm is given.

Brief on the working model and design:

Here we use ultrasonic signals of same frequency in the receiver and the transmitter and they cover a certain region of an area, when these signals are interference by a object the alarm is blown. Here we use ultrasonic transducers which are used for both input and output operations. To drive these transducers we use a two nand gates which is built around transmitter out of the four gates present in the IC3.

The devices connected to the IC3 form multivibrator which is used for driving the transducers. To make the output frequency to match with the resonance of the transducer we use a trimmer P2 by which we can adjust the frequency accordingly. Here we find the same transducer circuit in the receiver and the received signals are amplified by the transistor of the IC1 op amp.

The output of the IC1 is given to the IC2 and the amplification factor is adjusted by using P1. This acts as a inverting circuit and if the signals detect a object then the frequency changes occur in the signals and these signals are sent to the receiver due to frequency changes the distortion occurs which blows the alarm.


The proposed method is efficient way for detecting objects interfered by which we can provide security by blowing alarm. We can even use other methods for providing security but this is the effective method and requires low maintenance cost. By using this method the time interval for blowing alarm when the object is detected is very less.

Download  Electrical Seminar Topic and Report on Security Alarm Systems.