Cover page




Table of content


1.1 Introduction

1.2 Block diagram of an automatic phase changer 

1.3 Component list

CHAPTER TWO-Component description

2.1 comparator

2.2 Zener diode p.n junction,electron,avalanche diode,avalanche breakdown}

2.3 Rectifier

2.4 Relay

2.5 Transformer

2.6 Capacitor

2.7 Fuse


3.1 Comparator/voltage sensor stag.

3.2 Design calculator

3.3 Oscillator circuit

3.4 Flip flop/switching Transistor stage

3.5 Logic circuit

3.6 Transistor switching circuit 

3.7 Relay switching circuit 

3.8 Output load terminal

3.9 Methodology


4.1 Working

4.2 Performance evaluation

4.3 Circuit diagram

4.4 Planning of work 

4.5 Application



5.2 Recommendation

5.3 Reference


Raw power instability in developing countries creates a need for automation of electrical power generation or alternative sources of power to back up the utility supply.

         This automation is required as the rate of power outage becomes predominantly high. Most industrial and commercial processes are dependent on power  supply and if it processes of change-over are manual, serious time is not only wasted but also creates devices or machine damages from human error during the change-over connections,which could bring massive losses.The starting of the generator is done by a relay which switches the battery voltage to ignition coil of the generator while the main power relay switches the load to either public supply or generator.Fig 1 shows the generalized block diagram of the system.The approach used in this work  is the moduler  approach where the overall design was first broken into functional block diagrams,where each block in the diagram represents a section of the circuit that carries out a specific function.The functional block diagram fig 1 also shows the interconnection between these blocks.Each section of the block is analyzed below.A manual change-over switch consists of  a manual change over switch box,switch gear box and cut out fuse or the connected fuse as describe by the by rocks and Mazur{1993}.This change-over switch box separate the sources between the generator and public supply when there is power supply outage from public supply,someone has t go and change the line to generator.Thus when power supply is restored,someone has to put off the generator and then change the source line from generator to public supply.     

         In view of the above manual change-over switch system that involves man power in starting the generator and switching over from public supply to generator and vice-versa when the supply is restored.

          The important attached to cases of operation in hospitals and airport in order to save life from generator as fast as possible makes it important for the design construction of automatic change-over switch which would solve the problem of manpower and the danger likely to been countered changeover.

            The electronic control monitors the incoming public supply voltage and detects when the voltage drops below a level that electrical or electronics gadgets can function depending on the utility.

Fig 1 Block diagram of an automatic change over switch
















Component nameQuality

Step down transformer 3

(Files 22ov - 12v 300mA)

Fuse (F1 - F3 = 5A) 3

IC (IC1 – Ic3 =741) 3

Transistor (T1, T2, T3 = BC 557) 3

Relay (RL1 – RL3 = 12v LC/o Relay) 3

Zener diode CZD1 = ZD3 = 5, 1v 3

Variable resistance (VR4 – VR3 = 10K) 3

Resistance (R1, R2, R4, R5, R7,R8 = 3,3k 9

R3, R6, R9 = 10K)

Diode 9

Capacitor (C1 – C4 = 1000uf 25V 7

C5 – C7 = 470uf 35V)

Wires ACC, TO




RESEARCHWAP.COM is an online repository for free project topics and research materials, articles and custom writing of research works. We’re an online resource centre that provides a vast database for students to access numerous research project topics and materials. guides and assist Postgraduate, Undergraduate and Final Year Students with well researched and quality project topics, topic ideas, research guides and project materials. We’re reliable and trustworthy, and we really understand what is called “time factor”, that is why we’ve simplified the process so that students can get their research projects ready on time. Our platform provides more educational services, such as hiring a writer, research analysis, and software for computer science research and we also seriously adhere to a timely delivery.


Please feel free to carefully review some written and captured responses from our satisfied clients.

  • "Exceptionally outstanding. Highly recommend for all who wish to have effective and excellent project defence. Easily Accessable, Affordable, Effective and effective."

    Debby Henry George, Massachusetts Institute of Technology (MIT), Cambridge, USA.
  • "I saw this website on facebook page and I did not even bother since I was in a hurry to complete my project. But I am totally amazed that when I visited the website and saw the topic I was looking for and I decided to give a try and now I have received it within an hour after ordering the material. Am grateful guys!"

    Hilary Yusuf, United States International University Africa, Nairobi, Kenya.
  • " is a website I recommend to all student and researchers within and outside the country. The web owners are doing great job and I appreciate them for that. Once again, thank you very much "" and God bless you and your business! ."

    Debby Henry George, Massachusetts Institute of Technology (MIT), Cambridge, USA.
  • "I love what you guys are doing, your material guided me well through my research. Thank you for helping me achieve academic success."

    Sampson, University of Nigeria, Nsukka.
  • " is God-sent! I got good grades in my seminar and project with the help of your service, thank you soooooo much."

    Cynthia, Akwa Ibom State University .
  • "Great User Experience, Nice flows and Superb functionalities.The app is indeed a great tech innovation for greasing the wheels of final year, research and other pedagogical related project works. A trial would definitely convince you."

    Lamilare Valentine, Kwame Nkrumah University, Kumasi, Ghana.
  • "Sorry, it was in my spam folder all along, I should have looked it up properly first. Please keep up the good work, your team is quite commited. Am grateful...I will certainly refer my friends too."

    Elizabeth, Obafemi Awolowo University
  • "Am happy the defense went well, thanks to your articles. I may not be able to express how grateful I am for all your assistance, but on my honour, I owe you guys a good number of referrals. Thank you once again."

    Ali Olanrewaju, Lagos State University.
  • "My Dear Researchwap, initially I never believed one can actually do honest business transactions with Nigerians online until i stumbled into your website. You have broken a new legacy of record as far as am concerned. Keep up the good work!"

    Willie Ekereobong, University of Port Harcourt.
  • "WOW, SO IT'S TRUE??!! I can't believe I got this quality work for just 3k...I thought it was scam ooo. I wouldn't mind if it goes for over 5k, its worth it. Thank you!"

    Theressa, Igbinedion University.
  • "I did not see my project topic on your website so I decided to call your customer care number, the attention I got was epic! I got help from the beginning to the end of my project in just 3 days, they even taught me how to defend my project and I got a 'B' at the end. Thank you so much, infact, I owe my graduating well today to you guys...."

    Joseph, Abia state Polytechnic.
  • "My friend told me about ResearchWap website, I doubted her until I saw her receive her full project in less than 15 miniutes, I tried mine too and got it same, right now, am telling everyone in my school about, no one has to suffer any more writing their project. Thank you for making life easy for me and my fellow students... Keep up the good work"

    Christiana, Landmark University .
  • "I wish I knew you guys when I wrote my first degree project, it took so much time and effort then. Now, with just a click of a button, I got my complete project in less than 15 minutes. You guys are too amazing!."

    Musa, Federal University of Technology Minna
  • "I was scared at first when I saw your website but I decided to risk my last 3k and surprisingly I got my complete project in my email box instantly. This is so nice!!!."

    Ali Obafemi, Ibrahim Badamasi Babangida University, Niger State.
  • To contribute to our success story, send us a feedback or please kindly call 2348037664978.
    Then your comment and contact will be published here also with your consent.

    Thank you for choosing