Thesis Abstract

Abstract
The construction and design of police sirens play a crucial role in law enforcement operations by alerting the public and other drivers to the presence of emergency vehicles. This research project focuses on exploring the various aspects involved in creating an effective police siren system. The study delves into the historical evolution of police sirens, highlighting the technological advancements that have shaped their design over the years. The project involves a detailed analysis of the components that make up a typical police siren, including the speaker system, amplifier, and control unit. By understanding the functionality of each component, researchers aim to optimize the siren's performance in different environments and situations. Furthermore, the project investigates the sound characteristics of police sirens, such as frequency, intensity, and pattern, to determine the most effective auditory signals for alerting pedestrians and motorists. In addition to the technical aspects, the research also considers the ergonomic design of police sirens to ensure ease of installation and operation for law enforcement personnel. Factors such as size, weight, and mounting options are evaluated to enhance the practicality and usability of the siren system in various law enforcement vehicles. Furthermore, the project explores the integration of modern technologies, such as LED lighting and wireless connectivity, to enhance the functionality and visibility of police sirens. By incorporating these features, researchers aim to improve the overall effectiveness of the siren system in emergency response situations. The construction and design of police sirens are also examined from a regulatory perspective, taking into account industry standards and legal requirements for emergency vehicle warning systems. By adhering to these guidelines, researchers aim to ensure the safety and compliance of police sirens with established regulations. Overall, this research project provides valuable insights into the construction and design of police sirens, offering a comprehensive overview of the technical, ergonomic, and regulatory aspects involved in creating effective emergency vehicle warning systems. By optimizing the design and functionality of police sirens, law enforcement agencies can enhance their ability to alert the public and navigate through traffic safely during emergency response operations.

Thesis Overview

      INTRODUCTION
1.1 OVERVIEW
            A siren is a loud noise making device. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks. Sirens are used on emergency service vehicles such as ambulance, police cars and fire trucks. There are two general types of siren:

1-Pneumatic Siren
2-Electronic Siren
Many fire sirens (used for calling the volunteer fire fighters) serve double duty astornado or civil defense sirens, alerting an entire community of impending danger. Most fire sirens are either mounted on the roof of a fire station, or on a pole next to the fire station. Fire sirens can also be mounted on or near government buildings, on tall structures such as water towers as well as in systems, where several sirens are distributed around a town for better sound coverage. Most fire sirens are single tone and mechanically driven by electric motors with a rotor attached to the shaft. Some newer sirens are electronically driven by speakers. Though, these are not as common.
Fire sirens are often called “fire whistles”, “fire alarms”, or “fire horns.” Although there is no standard signaling of fire sirens, some utilize codes to inform fire fighters of the location of the fire. Civil defence sirens pulling double duty as a fire siren often can produce an alternating “hi-b” signal (similar to a British police car) as the fire signal, or a slow wail (typically 3x) as to not confuse the public with the standard civil defense signals of alert (steady tone) and attack (fast wavering tone). Fire sirens are often blasted once a day at noon and are also called “noon sirens” or ‘noon whistles”.
Pneumatic Siren consists of a rotating disk with holes in it such that the material between the holes interrupts a flow of air from fixed holes on the outside of the unit. As the holes in the rotating disk alternately prevent and allow air to flow it results on alternating compressed and rarefied air pressure i.e. sound. It consumes large amount of energy.
Electronic Siren incorporate circuits such as oscillators, modulators and amplifiers it synthesize a selected tone which is played through external speakers. It is not unusual especially in the case of modern engines, to see an emergency vehicle equipped with both types of siren.
1.2 PROJECT OBJECTIVE
          The main objective of this project is to implement Electronic Siren in both the software and hardware version. We are going to learn the PCB designing, Proteus software handling in an effective manner. At the end of this project student will be able to learn all these things. Electronic Siren is basically high-performance sound signal electronic amplifiers. These siren works with substantially higher outputs and specific demand are placed on them in terms of desired extreme reliability and different methods of control on them. Moreover control infrastructure must also be reliable and usually two independent control channels are required.
The loudspeakers for these amplifiers are placed in specially- designed sound battles and they play the signals stored in the siren’s digital memory or signals fed to the siren from external sources.
1.3 FUTURE SCOPE
It is possible to add an external signal source with these devices. Moreover it provides enhanced automatic testing. It is employed at user friendly level easily. In industry it will be a great advantage to the people.