Variable DC Power Supply

Abstract

Here we make a variable DC power supply and the main working principle of this project is full wave rectification which is done by bridge configuration. Where we are using 4 diodes and those rectifies the output of the step-down transformer, that stepdown the 220 AC volts to 12 AC volts. Here we also using a voltage regulator that gives constant voltage, which gives 6 volts and it is IC 7806 Voltage regulator. Now the main task is to get variable output and for this we use the pair of voltage divider resistors to increase the output of the regulator and in which resistance is variable. So when we increase or d ecr e ase t he valu e o f that r esis t or the ou tp ut vo ltage o f t he r egu lator will a lso change accordingly and we get a range of 0v to 12 v. and we also use a variable voltage regulator which gives 0v to 6v variable voltage. In this circuit we use three capacitor, C1 and C2 are used to get constant input to the regulator. Moreover it also helps to reduce the sharp peaks in the output. The 2700 µF and 100 µF capacitors are used to reduce the noise and ripples produce by the regulators. So that the regulated output has less ripples.