BSTRACT The scope of this project is to design, develop and test a power supply capable of taking an ac voltage and convert it into a regulated low voltage. The main working of this project is a full wave rectification which is done by bridge configuration in which four diodes are used to rectify the output the step-down transformer which steps down the voltage from 240v to 12 V.A Voltage Regulator is then used which gives a constant voltage. The main task is to get variable output by using the pair of voltage divider resistance to increase the output of the regulator in which the resistance is variable. So when increasing or decreasing the resistance of the resistor, also the voltage varies from 1Vto 12 V.The circuit also uses capacitors C1 and C2 to get constant input voltage to the regulator and also is used tosmoothen the rectified voltage to output.The power supply will be connected to the Zener voltage regulator that could supply to the load.

ABSTRACT The research aims at the designing and implementation of an automatic voltage regulator (AVR) with high precision and hysteresis. The AC power supplied by KPLC (Kenya Power) subjected to variation from time to time. Moreover, in rural areas supplied voltage remains lower than specified. This causes a considerable threat to the sophisticated electronic device to the computer, refrigerator, television etc. So, ensuring the input voltage to remain in a tolerable pre-specified limit has become a necessity in rural as well as some urban areas. Current system available locally lack precision and suffers the problem oscillating between two output voltage and hence creating surge at the output which can damage valuable electronics. This project handles both shortcomings and introduces the tolerable range of 12 1 voltage output. MERIT The circuit is simple but useful for wall AC/DC adaptors where it is important to reduce ripples and noise, and improve transient response of the adaptors. It can also be used in a wide range of switching and analogue power supplies. The circuit has been developed for 26V and 19V wall adaptors, but by replacing some components, it can be used for other wall adaptors with output voltage starting from 5V. When input polarity is fixed, the bridge can be replaced with simple diodes depending on requirement.

ABSTRACT The essential use of 12V lead acid batteries in automobile engines to power incorporated electrical appliances, and also the sudden failure of vehicle charging systems that often give rise to a drain of battery cells has necessitated the construction of battery chargers suitable for fully restoring the lost charge into the required 12V battery cells. Most 12V battery charging devices built for commercial services are usually heavy and bulky and lack a protection circuit and a sensitized control circuit required for automatic deactivation of charging once the battery is fully charged. In this new design product, the size of the battery charger was made portable and light in weight to enable end users to convey it as easily as possible. Short circuits and current reverse protection were incorporated as well. A sensitized control circuit was implemented to ensure that charging is terminated immediately when the battery is fully charged. This is to avoid the possible occurrence of overcharging that may result in loss of electrolytes. In this report the components used to actualize the design work were listed and the design specifications were tabulated with the circuit diagram well detailed. The operational principle of the built charger clearly explains how the design objectives were reached. An adopted formula with example on how to calculate the charging time of a battery when using the product was derived. Design limitations, recommendations, and conclusion were stated. Various relevant tests were conducted with its corresponding results tabulated. Finally, a well labeled image which lays out views of the completely constructed battery charger is attached in order to appreciate the effort and the value of the design work. (Keywords: AC power supply, rectification, charging, deactivation, full charge) Considering, the compact shape of the battery charger, with very low ventilation an extractor fan was incorporated to drive away hot air and moisture that would be generated inside the charger compartment during operation.

ABSTRACT An A.C and D.C fluorescent tube is useful for emergency blackout as it works on D.C as well, this saves the production process under lightings. This project comprises A.C components as well as D.C components under improved conditions, this makes it useful in both urban and rural areas. When A.C power is off user can supply it with D.C power to light the house or place as well Although fluorescent lamp is a very efficient lighting device in daily life, still the high harmonic distortion and low power factor cause unnecessary energy consumption. In today’s environment demanding energy efficiency, it is important to reduce this energy loss by integrating an energy saving controller in the electromagnetic ballast of fluorescent lamps. The research presented in this thesis investigates the design and implementation of a new energy saving controller for electromagnetic fluorescent lamp network. The newly developed controller attempts to reduce power losses in both the electromagnetic ballasts and fluorescent lamps by regulating the incoming supply voltage to an optimum level. In addition, the new controller is able to adjust the illuminance level of working environment lightings under either dark or bright condition. Moreover, the function of the new controller is extended with time scheduling control capability, where the switching of lighting systems can be controlled at predetermined times based on occupancy schedule. Both simulation and practical results show that the implemented controller reduces energy consumption by at least 37.5%, by reducing the incoming supply voltage by 15%. In addition, it is desirable to have variable illuminance level control to decrease the energy losses. The experimental results show that the illuminance output level of electromagnetic ballast fluorescent lamps can be decreased by 50% using the new controller while maintaining unity power factor. Integration of the new energy saving controller into electromagnetic ballast fluorescent lamps impressively outperforms the existing electronic dimmable ballast. This new controller brings great ideas for energy saving in the use of fluorescent lamps. Keyword: energy saving, illuminance level control, voltage control, electromagnetic ballast fluorescent lamps

ABSTRACT Conductor failure or outage in general does not promote development to public and private sectors. Development of our country and in addition, there are processes that need not to be interrupted because of their importance. This project presents the design, construction and implementation of a broken ac conductor for automatic detection of a broken ac conductor. Studies have shown that the electric fault which occurs in this facilities constitute the major cause of service interruptions as a result of their exposure to high currents, mechanical strains, utilization by the high currents consuming appliances used for a long time thus it’s difficult to locate the accurate location of the broken conductor. and because now days’ electric cables are being installed inside the walls using the pvc conduits or are being installed underground by the use of underground cables and because of this people generally replace the broken conductors instead of repairing them due to hardship in locating the exact place where the cable is broken therefore the reason of coming up with this project was to facilitate quick locating and isolation.

Technology development has made automation process simpler. The rise in population in the country increases demand for electrical knowledge, Security personnel and more application of electricity in their lives for better improvement and efficient services in homes and the country at large. The need of security is essential to human and living creatures. Considering the need of security we realized that the level of crimes such as theft is increasing, which causes poverty to low class people and class beings. Security is a vital tool in life as it helps people comfortably do business, live well hence encouraging investment the act of employing people to keep monitoring the area is expensive, Therefore a unit need to be designed to solve this problem. In considering the need of many I care up with infrared Based Security Alarm system which alerts one when the intruder interference with IR. i.e. when someone enters in a given area it turns on the security lamps and hence the Buzzer/ac alarm using Relay can produce sound hence detection at the intruder. Infrared based security alarm circuit an detect any movement trigger the alarm. THIS circuit is very useful in homes, banks, shops restricted areas where an alert alarm is needed on any movement. This circuit is based on IR sensor where an infrared beam is continuously falling on a photodiode and whenever this infrared beam breaks by any kind of movement alarm is triggered. Infrared sensor consist an infrared LED and photodiode in which IR LED emits infrared radiation and photodiode detects the radiation photodiode conducts current in reverse direction whenever light falls on it and voltages across it changes this voltages charge is sensed by voltages comparator i.e.(LM358) and generates output accordingly. In this infrared based security alarm circuit we have placed infrared LED in front of photodiode so that IR light can directly falls in photodiode. Whenever someone moves through this beam IR rays stop falling on photodiode and Buzzer start beeping . Buzzer automatically stops after sometimes as buzzer is connected to 55 timer in mono stable mode. OBJECTIVE Main objectives To design infrared based security alarm.

ABSTRACT This project explored the relevance of management systems to the contemporary society where computers have made tasks easier, more efficient and organized. Police record management system is a planned system of the storage processing and dissemination of data in the form of information needed to carry out various functions which come to simplify the tiresome manual way of reporting and writing the details on papers. There is need for an computrised record management system that can be used to store reported criminal activities in a centralized database which should replace the manual system that is currently being used. The manual system has few challenges that include the ever increasing paper load, difficulty in enforcing access control as well as cases of missing files and information. Our objective in regard to the project is to come up with an application that will be used to automate the manual management of Kenyan criminal records and hence the title “police management system (PRMS)”. Being a web based application; there is an assumption of users being connected to the internet. The scope of the project cuts across administrators and 2 types of clients; police officers and other clients: including private investigators, lawyers and other personalities seem fit by the Administrator to handle an account. The research methodology used in this project was System development lifecycle, using waterfall method simply because the project was small and there are no uncertain requirements. At the end of each phase, a review takes place to determine if the project is on the right path and whether or not to continue or discard the project The design was majorly aided by the dataflow context diagrams which are often used as a preliminary step to create an overview of the system. Use-case diagrams and activity diagrams also helped in coming up with the database class diagram which we used to develop the database. I faced some challenges in developing the systems in terms of having to learn new programming language on a short time frame and also experienced financial constraints on printing and buying of some devices that would have helped me to come up with better system like fingerprint scanner. In conclusion I would like to say that taking this project all through has been a wonderful experience for me. Without the practical knowledge that we acquired throughout the course, this project would not have materialized

ABSTRACT The center of this study was to develop and implement an Online Car Rental Information Management and Centralized Database System that helps in capturing the information from Customers and their Booking transactions. This was developed to reduce the effect of Manual System of Registering customers while booking. Therefore, the Project offers an extensive knowledge regarding Online Car Rental Information Management System from Africa one travels.thesyatem was developed using php MySQL HTML and CSS

This is a system documentation project report that documents the implementation of online compliant record system

This is accounting software notes lecture topic notes for computer application ll