Overview
An alternating current (AC) is an electrical current whose magnitude and direction vary cyclically, as opposed to direct current, whose direction remains constant. The usual waveform of an AC power circuit is a sine wave.
Like DC, with AC circuits, power is equal to volts x amps, but this is only true instantaneously. Thus the power at any one moment in time is equal to the Volts at that time multiplied by the Amps at that time. If we want to find the average power used, we must take the average of the power at each time interval. Mathematically this is known as Integration. The integral of a sinusoid over one full period is zero, because there is as much time spent below zero as above it.
This course provides a basic introduction to AC theory. The text is arranged to let you progress at your own pace, and concepts and terms are introduced as you need them, with many detailed examples and illustrations. This course will be extremely helpful to individuals who are just beginning a career in electrical work, or who require a basic knowledge of electrical principals and equipment to better their primary responsibilities. This course is also a prerequisite for the all other electrical training.
This 3-hr course material is based entirely on Naval Education and Training Materials (NAVEDTRA 14173), Electricity and Electronic Training Series; Module-2 “Introduction to alternating current and transformers” and covers Chapter 1, “Concepts of Alternating Current”.
The student must take a multiple-choice quiz consisting of fifteen (15) questions at the end of this course to obtain PDH credits.
Specific Knowledge or Skill Obtained
This course teaches the following specific knowledge and skills:
- The differences between AC and DC voltage and current
- The advantages of AC power transmission over DC power transmission
- The "left-hand rule" for a conductor
- The relationship between current and magnetism
- The methods by which AC power can be generated
- The relationship between frequency, period, time, and wavelength
- Compute peak-to-peak, instantaneous, effective, and average values of voltage and current
- Compute the phase difference between sine waves
Course
Click on the following link to the PDF document to review the course material before taking the quiz for credit.
Concepts of Alternating Current
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