This project involves the design and construction of an automatic power changeover that will change/transfer control from MAINS to Gen set and can automatically switch ON/OFF the Gen. The system incorporates a phase selector in MAINS and a switchover to Gen. It is designed in several blocks that are then combined to form a single functional unit. The first block is a +5v regulated DC power supply unit, the output of which is fed to the priority encoder and decoder blocks. The decoder’s output is used to select the phase in priority via a transistor driver stage and an electromagnetic relay that activates contactors. The Gen set, which contains circuitry that automatically starts and stops the Gen set, is the least prioritized phase. The system has been implemented. with the TTL chip market. LEDs and AC panel lamps are used to indicate system status, while a manual switch is used to demonstrate system operation mode.



Industrial automation and control have made significant contributions to the world’s rapid technological advancement. Power control and automation are aspects of this field that are used almost anywhere electrical power is used, generated, or transmitted. Manual power change-over switches have existed in various forms and shapes. The introduction of microelectronics in 1959 paved the way for the modification of manually operated change-over switches. This project is about designing and building an automatic change-over switch with an indicator. It saves time and energy spent on manually changing over and starting the generator. It is completely automated. It can be used in homes, offices, and, most importantly, factories that require a continuous power supply. It has a lot of There are numerous advantages over existing ones/types.


This project work is being undertaken in order to eliminate nearly all shortcomings associated with the manually operated type in order to ensure that it is fully automated.

This system is realized as a series of functional blocks that are all combined to form a single functional system. The first block is a 3-phase MAINS regulated dc power supply unit that both powers and serves as the input to the overall circuit. The thin block output is routed to a priority encoder (74147), which selects the most prioritized phase at a time. The third component is a BCD-to-DECIMAL Decoder (7442) that is used to decode the prioritized phase.

The fourth stage is the driver stage, which is made up of an NPN transistor that powers the electromagnetic relay, which switches the phase in priority. The section on gen set switching is accomplished by utilizing the phase with the lowest priority. When all of the NEPA phases are low, OFF, or faulty, this section turns on the generator. When the Gen set phase is selected, a switching transistor fires an SCR, which conducts a large battering current to the Gen set’s ignition coil. Panel indicators are used to display the system’s status.


The primary goals of this project are to design and build an automatic change-over switch with Gen set switching capability capable of transferring control from MAINS to Gen set.

It is also intended to provide the graduating student with hands-on experience that will be invaluable in their professional practice. It is intended to provide a solid foundation for EEE graduates in electronic system designs involving power control and automation using random/hard wired logic. Another goal of this project is to educate graduating students on engineering ethics, technical and scientific writing, which is the foundation of engineering professional practice.


This project work is significant in the field of electrical power control and automation. It has a lot of weight in EEE. This project is a design that must be developed and funded for commercial purposes in order for it to be useful. This project eliminates the stress, time delay, and other disadvantages associated with manually operated types. Using a single seven segment display and the appropriate circuitry, the project can be modified to display the phase in use at a specific time. It also introduces students to digital system designs that use encoders and decoders.


The design and construction of an automatic change-over switch with Gen set switching capability is the focus of this project work. It discusses encoders and decoders, relays/contactors, a three-phase regulated DC power supply unit, passive and active components, the generator switching mechanism, and the mode of calculation of the basic circuit parameters used in the design.


This project report is divided into six chapters to better illustrate the steps involved in its execution.

The first chapter introduces the project overview, objectives, and significance. Chapter Two consists primarily of a literature review and some design-related theories. The methodology and analysis are examined in Chapter Three, while the system design and description are covered in Chapter Four. Chapter Five goes over the implementation, testing, and outcome. Finally, Chapter Six is a summary of all theories and recommendations.


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