Electric Motors

Figure 1-5 Simple block diagram of an electric vehicle.

Electric Motors

Electric motors can be found in so many sizes and places, and have so many varied uses, that we tend to take them for granted. Universal in application, they can be as big as a house or smaller than your fingernail, and can be powered by any source of electricity. In fact, they are so reliable, quiet, and inexpensive that we tend to overlook just how pervasive and influential they are in virtually every civilized person’s life.

Each of us encounters dozens, if not hundreds, of electric motors daily without even thinking about them: The alarm clock that wakes you; the television you turn on for the news; you remove coffee beans from the refrigerator and put the coffee beans in a grinder; in the bathroom you use an electric shaver, electric toothbrush, or hair dryer; breakfast might be assisted by your electric juicer, blender, or food mixer; you might clean your home with your vacuum cleaner or clean your clothes with your washer and dryer; next you’re into your automobile, subway, bus, or light rail transit to ride to work, where you might go through an automatic gate or door or take an elevator or escalator to your floor; at home or at work you sit down at your computer, use the Internet, e-mail, cell phone, or Blackberry, and use your fax or copier after you adjust the fan, heater, or air conditioner. Back at home in the evening, you might use an electric garage door opener, program your TiVO, or use an electric power tool on a project. On and on, you get the picture.

Why are electric motors ubiquitous? In one word—convenience. Electric motors do work so that you don’t have to. Whether it’s pulling, pushing, lifting, stirring, or oscillating, the electric motor converts electrical energy into motion, which is further adapted to do useful work.

What is the secret of the electric motor’s widespread use? Reliability. This is because of its simplicity. Regardless of type, all electric motors have only two basic components: a rotor (the moving part) and a stator (the stationary part). That’s right—it has only one moving part. If you design, manufacture, and use an electric motor correctly, it is virtually impervious to failure and indestructible in use.