Designing of Laboratory D. C. Regulated Power Supply

The most used electronic equipment in the laboratory is D. C. regulated power supply.There are requirements of fixed voltage source, constant current power supply, or variable power supply.This paper deals with lowcost, portable fixed and variable D. C. regulated power supply using diode, transistor, and regulated ICs.In this paper, we make fixed and variable dual power supply by using rectification which is done by using four diodes and step-down transformer.Design a fixed and variable regulated power supply using various types of transformers.The circuit has been designed using transistors, IC78XX & IC79XX, LM317, and LM337 for fixed or variable voltage and a dual power supply.