15-STEP DIGITAL POWER SUPPLY

INTRODUCTION
This circuit will obtain variable DC voltage from 1.25v to 15.19v in reasonably small step.
The steps are according to binary codes.
These codes are obtain using Up Down counter.
This circuit works on the digital principles as we are using binary codes.
OBJECTIVE
This circuit use to we can obtain the 15 step from 1.21 to 15.19v output voltage.
This circuit give variable output voltage. (+ve) Positive and (-ve) Negative
Use LED to indicate variable 15 step voltage.
Compare with normal power supply
This circuit we can get variable output voltage in one terminal (separate Positive & Negative)
The normal power supply that used different output voltage to different terminal. example 5v,9v,12v,15v
WORKING
When the power is switched on,IC2 resets itself
The output at pins 6,11,14 and 12 is equivalent to binary zero i.e ‘0000’
The corresponding DC output of the circuit is minimum(1.25V)
As count-up switch S1 is pressed, the binary count of IC2 increases and output starts increasing too
At the highest count output of 1111,the output voltage is 15.19V