Understanding Alternating Current
In This Chapter
Discovering and using alternating current
Converting mechanical power to alternating current
Working with electric motors
Stepping up and down with transformers
When you paddle in a river as a child, you can feel the cool water flowing between your toes and the current flowing steadily in one direction. Water doesn’t flow uphill and so a river always flows one way, towards the sea.
Direct current (DC), as with the current you get from a battery, is like that – it flows only one way around the circuit and carries on doing so until you switch it off or turn the battery around so that the current goes the other way. For example, in Book III we focus mostly on working with DC and electric current flowing in one direction only.
Paddling in the sea, however, feels quite different to a river. You still sense the cool water around your toes, but it doesn’t just go one way. The waves sweep in over your feet, and then you feel the water pulling the sand from under you as the water recedes. Another wave comes in, and then the water ...