Design of low cost programmable DC power supply unit

The main scope of this work is to design a low cost programmable DC power supply unit for electronics laboratory. The system designed provides a low cost solution with specifications needed for electronics laboratory. The power supply unit is an open loop control system which is designed using a buck regulator IC and the controller uses PIC24FJ64GA002 microcontroller which provides control signal to the unit to achieve the programmed voltage at output terminal. Control panel with matrix keypad and alphanumeric character LCD is a part of controller which provides user interface to feed - the control input and to display the output values. The proposed system has triple output DC power with voltage ranges from 0V to +/-12V and a short circuit current limiter is provided to give short protection and current limiting at the output terminal of unit. The system has been successfully developed and hardware verification using PIC24FJ64GA002 microcontroller has shown that the system is working as expected with satisfactory results.