Power Electronics is the process of controlling the flow of current and voltage, converting it into a form that is suitable for a specific user load. At the heart of this process are specialized semiconductor components that function as high-speed electronic switches. These devices are the fundamental building blocks that allow us to manage electrical energy with precision and efficiency. In this primer, we will explore five of the most essential power switching devices that make modern electronics possible: the SCR, TRIAC, BJT, IGBT, and MOSFET.

Understanding these components is the first step toward understanding how everything from a simple light dimmer to a complex electric vehicle manages its power. Let’s begin with the workhorse of high-power control.