Automatic Two Phase Changer Over

Description

Automatic Two-Phase Changer Over is user-friendly and easy to use. It saves time too. This project is also a prototype for the automation of the system. In the earlier days (even today at some places) the manual operations are frequent. When phase 1 goes off the person manually turns on phase 2. In the case of the electrical appliance control using automation causes more safety. This kit is a prototype for the same which is auto change over to phase2 when main phase 1 fails. In this kit, we are designing a circuit to control this. In case there are two phases, then the switching will be in the default phase.

The Automatic Two-Phase Changer Over Circuit is built around a transformer, capacitors, regulators, gate IC, and relay. Two identical sets of this circuit, one each for two phases, are used. The mains power supply phase 1 is stepped down by transformer to deliver 12V, 300 mA, which is rectified by a bridge rectifier and filtered by the capacitor to produce 12V DC regulated to 5V using 7805.

• A similar process is done with phase 2 to get 5V. Proper logic is implemented using the gates IC7404 (NOT) and IC7408 (AND) so that only one phase is activated when both the phases are available.
• if any of the phases go off the available phase is activated.
• The output from the gate logic is fed to the ULN2803 IC relay driver to put on/off the phase supply (activation and de-activation.)