There are any number of electric motors in your house; just open up any appliance and look inside. Even your DVD player and your hand mixers use motors. All these domestic motors run on electricity.
There are three types of electric motor. Universal brush motors have high torque and variable speed; you’ll find them in drills and washing machines. Induction motors are silent, safe and reliable. They are found in refrigerators and pumps. New motors coming on the market, on the other hand, try to combine the best of both these worlds. These new motors are very exciting because they combine the high torque of brush motors with the silent durability of brushless.
Microcontrollers have been a part of the modern appliance for years, usually making their appearance in the switches and knobs that make them work. Now these tiny controllers are making their way inside the appliance, as well, controlling the current in an induction motor. Variation in current allows the motor to operate at different speeds.
Whether you are running a food processor or a Poulan chainsaw, variable speed is what you need for optimum efficiency. Speed control can boost efficiency, in some cases by as much as 30 percent. These smaller motors also allow manufacturers to charge less for their products.
For large motors, like those used in washing machines, the microcontrollers are not a viable solution. The controllers are just too expensive. Instead, these motors are built with the new permanent magnet technology. They run at variable speeds, they run quietly, they don’t produce much waste heat and they save energy. They save water, too!
In fact, these permanent magnet motors are getting more and more popular. Because they use less raw material, such as copper and steel, their price points are less affected by the swings of the commodities market. And as their popularity grows, the overall prices of the magnets comes down, as well. Even now they are used in everything from cars to cell phones.
Of course, these wonders won’t work in every appliance. You won’t find one in your Homelite chainsaw any time soon, for example. But you will start seeing them more and more in refrigerators, drills, washing machines, pumps. With the high torque of traditional motors combined with the silent dependability of an induction motor, we have a perfect match.
