This document describes an experiment using voltage regulator integrated circuits to regulate voltage from an unregulated power supply. The objectives are to design a fixed voltage regulator circuit using either a 78XX or 79XX IC and learn how to use voltage regulator ICs to provide positive or negative fixed voltages. The document provides background on voltage regulators, an overview of common regulator IC types, and procedures for building circuits using 7809 and 7909 ICs to regulate 9V from an unregulated 22V supply and measure the output voltage and current. Tables compare theoretical and experimental values obtained.