Variable Power Supply using LM317 Voltage Regulator

Until now we had discussed about different voltage regulator IC's including 7805,723 etc but what's to be noted was that these were all fixed voltage regulators.So now we shall see how design a simple variable voltage regulator using an LM317 IC.

Block Diagram

This circuit, like all voltage regulators  must  follow the same general block diagram Block Diagram of Power Supply Here, we have got an input high voltage AC going into a transformer which usually steps down the high voltage AC from...