Smart Phase Change-over system with AT89C52 Microcontroller

Abstract

This project is designed to check the availability of any live phase, and the load will be connected to the live phase only. This feat is achieved with AT89C52 MCU. This controller continuosly checks for live condition of all the phases connected to it, and the controller connects the load the load to the active phase Relay, live phase, controller, rectifier, using a relay. The relay is driven with a transistor. If two or three phases are live, the phase will be connected to the phase that is ON only and automatically transferred to the phase that is ON in the event of a main outage or from generator back to main when restored. An LCD is provided to display the status of the phase condition. Conrast control preset is given for LCD contrast control.. Furthermore the project uses a regulated 12V, 500mA power supply. Bridge type full-wave rectifier was used to rectify the a.c output of the secondary 230/12V step-down transformer.