DESIGN AND CONSTRUCTION OF AN OVER VOLTAGE AND UNDERVOL TAGE CUT-OFF SYSTEM.

Abstract

This project is designed as an improvement over the traditional fuse system used in electrical installations today. The input is obtained from the power supply company and then stepped down to 24V. The stepped down voltage is then converted to direct current (DC) and then divided into two equal halves. One of the halves is regulated to remain at 12V before it is being sent to the comparator stage while the other is not regulated before it is sent to the comparator stage. Three scenarios occur at the comparator stage. First, as long as the input is not less than 180V or greater than 240V, the regulated voltage would always give an output in the comparator stage while the unregulated voltage would not give an output in the comparator stage. In this stage, there would be an output from the comparator stage to drive the: load. Secondly, if the input voltage is greater than 240V, both the regulated and the unregulated voltage would give outputs in the comparator stage. In this case there would be no output from the comparator stage to drive the load. Finally, if there is no input voltage or the input voltage is less than 180V, there would be no output from the comparator stage neither would there be any output voltage to drive the load. The project is designed with the following objectives in mind: • First objective is to put to use all that I have learnt in my undergraduate years to solve one of Nigeria's major problem. • Secondly, inline with the purpose of the use of a fuse, this project serves as a protective means to all electrical installations and devices. • Finally, this project is not a complete replacement to the conventional fuse system used today in electrical installations and devices, but it serves to create a redundant system for safety.