This course introduces students to the fundamental concepts of power electronic circuits and the application of semiconductor devices in power converters. Initially, the definitions used and the basic operation of switching converters using ideal switches are introduced. Subsequently, the structure and operation of power switches such as diodes, bipolar junction transistors, MOSFETs, IGBTs, and the thyristor family (IGCT, MCT, GTO, and SCR) are examined. Following this, driver circuits, protection circuits, and auxiliary equipment such as heat sinks are introduced. Finally, various topologies of power converter circuits including rectifiers, DC/DC converters, and inverters are analyzed and reviewed. Ultimately, topics on protection against overvoltage and overcurrent are discussed.