Introduction:

This paper mainly emphasis on the working of LM317 regulated power supply. LM317 can be the best option for providing protection to the complicated complex circuits. LM317 is a three terminal adjustable voltage regulator. This type of voltage regulators have output voltage in the range of  1.2 to 5.7volts and output current in the range of 0.1 to 1.5amperes. It has a capacity to develop a reference voltage of 1.25volts between the a adjustable terminal and output.

Regulated Power Supply Circuit design Using LM317:

The 230V AC coming from the grids is fed to step down transformer through a on off switch and 500ma fuse. The 30v AC output coming from transformer is converted to DC current by using Bridge rectifier. To eliminate the remaining AC components we need to filter  it by using 2200mf capacitor and the capacitor output is fed to LM317 regulator , where the voltage is adjustable in between 1.2 to 30volts, which is varied by using a 5k potentiometer. To protect the circuit from reverse currents a feedback is given by using a diode. By the addition of diodes and capacitors it acts as a protective circuit.

Future scope:

There are certain future prospects, one of them is noise effect of the circuit which is to be overcome so that we can get an error free output voltage. Thus we can conclude that by completely we can design a highly efficient power supply which gives protection to complex circuits from getting damaged.

Download Regulated Power Supply Using LM317 Project Report.