The aim of this project is to construct an intelligent system, capable of selecting active phase from three phase supply.  The system continuously monitors all the phases of the supply and switches ON the single-phase load from the active phase. If three phases or two phases is active, the system automatically selects any one of them. If all the phases are OFF, load will be automatically OFF. The main controlling device of the whole system is a Microcontroller. Single phase selection circuit, LCD and Relays are interfaced to microcontroller. Microcontroller continuously monitors three phases and selects the active phase from the input fed from single phase selection circuit. The selected active phase will be supplied to the load through relays connected to Microcontroller. Microcontroller displays the phase information on the LCD screen.      

The objectives of the project are:  

1. Automatic selection of active phase from three phase supply.
2. Switching ON the load from the active phase.
3. Displaying phase information on LCD screen.

      The major building blocks of this project are:   

1. Regulated Power Supply
2. PIC Microcontroller.
3. LED Indicators.
4. Relays with driver.
5. Crystal
6. Reset
7. Single phase selection circuit
8. LCD with driver.

        Software’s used:

1. PIC-C compiler for Embedded C programming.
2. PIC kit 2 programmer for dumping code into Microcontroller.
3. Express SCH for circuit designing.

        Regulated power supply:

             

Block Diagram:      

video: