The present book, designed for polytechnic and undergraduate students of electrical/electronics, is written in a simple language with solved examples. Short questions and answers are given at the end of many chapters. Due emphasis has been given to elaborate the fundamentals. All the steps of the derivations are furnished. Sufficient numbers of diagrams are given to improve the clarity of the subject. This book will serve as an ideal text on power electronics and industrial electronics for undergraduate and polytechnic students. It will also be very useful for those preparing for professional courses like AMIE and AMITE.