Electrical Theory and Circuits

Most electricians learn what to do. This course teaches you why it works. Starting with DC circuits, you'll move past Ohm's Law into the analytical tools that let you solve real circuits with multiple sources and components: Kirchhoff's Laws, Thevenin's theorem, and the transient behavior of capacitors and inductors. From there, you'll tackle AC theory, where time-varying currents introduce phase relationships, impedance, and resonance. By the end of Unit 2, you'll understand three-phase power well enough to work with it, not just around it. The second half of the course focuses on two things that separate journeymen from master-level thinkers: power factor and transformers. You'll learn why not all power in an AC system does useful work, what reactive power actually is, and why poor power factor shows up on a commercial electric bill. Then you'll get into transformers: how they step voltage up and down, the math behind sizing them, and the winding configurations you'll encounter throughout distribution systems. This course is built for working electricians and apprentices who want the theory behind the trade, as well as anyone studying for a licensing exam or an electrical engineering prerequisite. The material progresses from foundational to advanced, and each unit connects the math to something you'd encounter in the field. You don't need calculus, but you do need to be comfortable with algebra and willing to work through problems.