# 3: AC Generation

• 3.1: Electromagnetic Induction
Electromagnetic induction is when a voltage is created by passing a conductor through a magnetic field.
• 3.2: The Alternator
We have established that if we have a conductor pass through a field or a field through a conductor a voltage is established. This means that voltage is only established when there is constant motion. Instead of having someone passing a conductor through a field rapidly, it was discovered that the conductor could be formed into a loop and rotated through the field to maintain a voltage. This would be an example of what is known as a simple alternator.
• 3.3: How a Waveform Is Generated
Any time you pass a conductor through a magnetic field, you induce a voltage. If we take that conductor and turn it into a loop and spin it continually through that magnetic field, we have created an alternator. This means that a voltage will constantly be induced. However, this is not a flat line voltage like direct current. It creates an oscillating voltage that rises and falls.
• 3.4: AC Waveform Analysis
Well, it turns out that there is an awful lot going on in that waveform. Most of it is actually useful as well.
• 3.5: Frequency and Alternators
In the last chapter, we learned the term cycle means from the point in a waveform to where the waveform starts to repeat itself. When we discuss the term frequency, we are referring to how many cycles can occur in one second. Frequency is measured in hertz or CPS (cycles per second). Two factors affect the frequency in an alternator: rotation speed and the number of poles.

Thumbnail: Simple Alternator