Solving circuits with differential equations is hard. If we limit ourselves to sinusoidal input signals, a whole new method of AC analysis emerges. Created by Willy McAllister.

Circuit analysis is the process of finding all the currents and voltages in a network of connected components. We look at the basic elements used to build circuits, and find out what happens when …

Here's a preview of how AC analysis is going to work. To get ready we need to review some of the ideas from trig and complex numbers.

So, in our heads and on paper, we can actually draw circuits with these things. We can't actually build it but on paper, we can do it. Now that I have two sources, I can use the principal of superposition. This …

If we introduce time as the argument to the sine function, we get a sine wave. Animated.

This is a really important idea in electronics and it's something that comes from the study of AC analysis. And AC analysis is where we limit ourselves to inputs to our circuits that look like sinusoids, cosines …

Euler's formula relates the complex exponential to the cosine and sine functions. This formula is the most important tool in AC analysis. It is why electrical engineers need to understand complex numbers.

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What is the phase difference between 3 phase AC sine waves and how can we calculate them?

Circuit analysis, or solving a circuit, means figuring out voltages and currents in each element. Here's an overview of circuit analysis, with some context for the various tools and methods we use to analyze …