Project concept note on
OVERVOLTAGE AND UNDERVOLTAGE PROTECTION OF
DOMESTIC LOADS
STUDENT NAME:YOHANA PASTORY
Reg.No.BSCEE 44831
Contact.0752481860
Academic year.2018/2019
Date.11/01/2019

1.1.contextual Background
•
Power supply fluctuation in Tanzania causes domestic loads like Radios, Television and Fridges to be subjected to Over voltage and Under voltage, which may damage the equipments.
•
The protective device to be designed must be able to detect the unusual voltage and stop the supply to the domestic loads
1.2.issue [problem]statement.
•
The main problem is the power fluctuation in which the supply voltage rises above or falls below the acceptable limits of the nominal value (In Tanzania it is 230 + 6%
).
•
The voltage protective device to be designed will solve this problem by detecting the abnormal voltage and stops it from reaching the domestic loads.

2.0. INTENDED ACTION AND ITS
SPECFICATION
2.1. Intended action & its specification
The designed will solve this problem by detecting the abnormal voltage and stops it from reaching the domestic loads.
2.2. System requirement and constraints

The system should have ability to detect voltage level

The system should operate automatically

System should have very sensitive sensor to detect voltage level

2.3. system block diagram(conceptual model)
Step down
Transformer
RECTIFIER FILTER
CIRCUIT
Visual indication relay control circuit comparator comparator
AC POWER
12V +Ve voltage
Regulator

•
•
•
•
3.1. Main objectives
To design of an electronic circuit for detecting abnormal supply voltage under/over the nominal voltage.
3.2. Specific objective
Design of a rechargeable DC power supply with battery overcharging and undercharging protection to power the electronic control circuit.
To provide a means of protecting the device from surges
Upon detecting the abnormal supply, the supply should be switched off to the load after the delay time of 40ms.
When the normal supply(194V-243.8V) is detected from off position, the power should be switched on to the load automatically after a delay time of 40ms.

4.1.Depth &breadth of treatment.

This will focus on the specific objectives.
4.2. Study context or operational environment.

Design of this system will be implemented in residential houses industrial and oficces.
4.3. Key deliverables/outcomes expected.

The outcomes of this project is to solve the problem of lost electrical equipment due to fluctuation of voltage level.