DESIGN AND CONSRUCTION OF AN ELECTRICAL POWER FAULT CIRCUIT INTERRUPTER

Abstract

The system is designed for under voltage and over voltage fault protection. It continuously measures line voltage actual condition in an electrical wiring outlet to a safety limit and disconnects power supply to the load if actual voltage exceeds the limits before they become damage or ignite fire. In certain circumstances, household wiring and appliances have been the source of fires in the home due to over voltage supply, overload and the oxidation of the wire or wear over time. This involves step down transformer, LM324 voltage comparator that senses input line voltage and generate an output which is connected to the base of 2N2222 PNP transistor. The system also used 555 timers Ie for alann and electromagnetic relay was also used for switching and driving of alann. The device detects over and under voltages to the load in the outlet. With this infonnation, voltage comparator is used to evaluate whether a voltage difference exist at the load. When the predetermined voltage threshold is met, the logic switching circuit executes an emergency shutoff so that current to the appliance at that particular outlet is tenninated and sound an al~nn to notify the user