Project on Design and Fabrication of Under/Over Voltage System

This project details the design and fabrication of an under voltage and over voltage protection system, a crucial component in electrical and electronics engineering. The project aims to protect electrical loads from voltage surges and fluctuations using an auto cut-off circuit built with transistors and discrete elements. The project involved designing both under voltage and over voltage protection mechanisms. The author's responsibilities included providing technical support, resolving electrical issues, researching voltage protection methods, and documenting the project. Key activities included assessing and improving electrical systems, applying mechanical aptitude, and understanding the theory behind voltage protection circuits, including transformers, capacitors, and potentiometers. The project addresses issues such as power quality and suggests solutions like grounding, bonding, and proper wiring. The ultimate goal was to produce a reliable and cost-effective protection system through collaborative work and task segregation.

CE 3.1 Project Information
Name of the project: Design and Fabrication of Under Voltage and Over Voltage
Protection System
Location of the project: Please fill
Project Duration: Please fill
Organization: Please fill
Role and Designation during the time: Team Member of the project
CE 3.2 Project Background
CE 3.2.1 Characteristics of the project
The project of Design and Fabrication of Under Voltage and Over Voltage Protection
System was my first mini project in electrical and electronics engineering career. The on time
delayed circuit is not only responsible for protecting the loads from the switching surge but
even from the quicker changeover or the off or on effect. The inexpensive auto cut off circuit
is present here that is being fabricated with the help of the transistor and the other discrete
elements. This could be utilized for protecting the loads like television, refrigerator, and the
VCR from the undesirable over as well as under line voltages, and the surges that are caused
for the sudden failure or resumption of the major supply of power. This particular circuit
could be utilized directly as the standalone circuit within the main supply or the load, or this
might be inserted within an existing automatic or manual stabilizer or the load.
CE 3.2.2 Objectives developed for the project
This particular project of Design and Fabrication of Under Voltage and Over Voltage
Protection System consisted of various important objectives. They are given below:

 To design and fabricate under voltage protection system.
 To design and fabricate over voltage protection system.
CE 3.2.3 My area of work
The project of Design and Fabrication of Under Voltage and Over Voltage Protection
System was the third important project in my engineering career. I had several areas of work
in this particular project. My first major area of work was to provide technical support as well
as resolution when all the electrical problems were being encountered. My other area of work
involved researching about under voltage and over voltage and documenting the project
report properly. This project documentation was done by me perfectly.
CE 3.2.4 Project Group
Figure 1: People involved in the project
CE 3.2.5 My responsibilities throughout the project
I had some of the major responsibilities in this particular project. The first and the
most important responsibility in this project was collaborating with the electrical engineers

and all other parties for identifying, defining and resolving the electrical technical issues or
problems. The test information regarding electrical equipments was analyzed and interpreted
by me. Moreover, I even planned for the electrical installations for minimizing waste of
materials and thus provided access for the future maintenance. The repair of the electrical
systems and the wiring including various other factors, however, not limited to the power
distribution systems, control panels, lighting systems, components of the machineries or
equipments, fire systems, security camera infrastructures and data wiring. The higher voltage
switching was performed by me and even generators were operators in support of the
operations at transmission plants. My other responsibilities were modelling, implementing
and complying with the electrical safety rules or related industry regulations.
CE 3.3 Distinctive Activity
CE 3.3.1 Engineering knowledge and skills applied in the project
I had applied some of the major skills in this particular project. The most important
skill that I have applied here to design the protection system of under voltage and over
voltage was assessment and improvement of electrical systems for the increased demand.
Moreover, I utilized my designing skills and knowledge in this project and hence the
protection system was made properly. Mechanical aptitude was the next significant applied
here. The intense knowledge of mechanics was required here for making the protection
system properly.
CE 3.3.3 Comprehending the Theory of Project
The protection circuit of under or over voltage with the time delay that was being
presented by us was the lower cost as well as the most reliable circuit to protect the
equipments from various damages. Whenever this line of power was switched over, it was
getting connected or linked to only appliance after the fixed time delay. This system tried for

the connection of the power back when the time delay was counted from disconnection time.
The circuit had been eventually designed, built or even evaluated by me for using as the
protector. This was designed with the available semi conductor devices like the standard
bipolar medium power NPN transistor or D313/ SL100/ C1061, and NE555 timer IC.
The transformer can be defined as the device of static electric, which transfers the
energy by the inductive coupling with two or even more of the windings. The varying current
within the most important winding created the varying magnetic flux within the core of
transformer and hence the magnetic flux throughout the less important winding. The
magnetic flux induced the varying EMF or electromotive force, or the voltage, within the
minor winding.
The voltage that is being induced across this secondary coil was calculated from the
Faraday‘s law of induction that states:
Where, Vs is instantaneous voltages, Ns is number of the turns within secondary coil
as well as Φ is magnetic flux during any one turn of coil. When the turn of coil is being
oriented perpendicular to the lines of magnetic field, this flux is product of magnetic flux
density B or the area A by which this is cutting. The specific area is constant, and thus being
equal to cross sectional area of transformer core, however the particular magnetic field
eventually varies with time as per the primary.

Figure 2: Ideal Transformer as the circuit element
The conducting materials utilized for all the windings is dependent on the application,
however in all the cases the specific individual is responsible for turning should be insulated
electrically from one another for ensuring that this current is travelling through each and
every turn. For the smaller power as well as the signal transformers, where the currents are
extremely lower and hence potential difference within the adjacent turn is smaller.
The respective capacitor is the model for all electric fields in the electric circuits. The
ideal capacitor can be subsequently characterized by the typical constant capacitance C, and
could be defined as typical ratio of charge ±Q over every conductor with the voltage V within
them. This is given as:
The current I(t) by any specific component within the electric circuit can be defined
as a rate of charge flow Q(t) passing from it, however the actual charges electrons could not
be passing from the specific dielectric layer of the capacitor. The easiest capacitor comprises

of the two typical parallel conductive plates detached by the dielectric with the permittivity ε.
This model might also be utilized for making the qualitative prediction for any device
geometry. All the plates were considered for extending uniformly on the area A and the
charging density ±ρ = ±Q/A that is existing on the surface.
The potentiometer could be utilized as the voltage divider for obtaining the adjustable
output voltages at the wiper from any fixed input voltage that is being applied across two
distinct ends of potentiometer. This could be the most common utilization of them. This is the
inexpensive auto cut off circuit that is being fabricated with the help of transistors and all
other discrete elements.
CE 3.3.4 Identified issues and their solutions
3.3.4.1 Issues
I had faced some of the major issues in this particular project. The first issue that I had
faced here was the issue of power quality. The widespread utilization of the electronic
equipments like the information technology equipments was the major problem that we had
faced here. The PLC or programmable logic controllers and the ASD or adjustable speed
drives were the examples of power electronics and thus leading to the total change of the
electric load nature. All of the loads were the main causers as well as the main victims of the
problems that are related to power quality. For the reason of non linearity, the specific loads
that had caused disturbances within the waveform of voltage were faced by us.
3.3.4.2 Solutions
To solve all of these above mentioned problems, I suggested some of the easiest
solutions. For the first significant issue of power quality, I gave the suggestion of grounding
and bonding. Grounding can be defined as one of the most significant aspects of electrical

systems. The specific safety ground is responsible for protecting the electrical systems and
the equipments from all the super imposed voltages that are caused by the lightning or the
accidental contacts with the high voltage systems. For the next issue, I provided the
suggestion of proper wiring. The total equipment inspection was the most crucial factor for
ensuring proper wirings within the facility. The complete electrical system must be
eventually checked for the loose, missing or even the improper links at the panels and the
equipments.
CE 3.3.5 Plan to produce creative and innovative work
My major plan was producing innovative as well as creative work by simply working
collaboratively. I even segregated the total work perfectly and every task was being executed
perfectly.