The performance of each and every electronic system or electronic circuit depends upon the power supply that energizes the circuit or system. It provides required current to the circuit. Any disturbance noise in this power supply can cause problem in working or operation of circuit. If there is any deviation in this power supply level the circuit may not work properly. The accuracy and precision of circuit operation depends upon it.  In some of the circuits all the calibration are done at this voltage level. So all these calibrations becomes false if there is fluctuation in supply level.  There are two types of power supplies: Unregulated power supply, Regulated power supply. Unregulated supply is used in some circuits where there is no much change in required load current. The load current remains fixed or deviation is very less. Read more to know about this interesting power supply project.