Electric motors have been around for quite a while now, but you still might not know how they actually work. If you don’t, then you’re in the right place. In this article, we’re going to look into electric motors in a bit more detail to work out how they really work.
Electric motors helped to revolutionize the modern world. Not only are they’re a big part of many different technologies. They’re also reasonably complicated. But don’t worry, if you keep reading this article, you’ll find out a bit more about how they work as well as what you can use them for.
So how do electric motors work? Let’s have a look…
Electric motors are used in so many different items around the home. There are both alternating current (AC) and direct current (DC) motors. A basic electric motor is made up of a rotor (or armature), a commutator, brushes, an axle, a field magnet and a DC power supply. Motors use all sorts of different scientific principles and are based on magnets, electromagnets and electricity.
Motors use the motion that magnets can create. They use the simple attraction and repulsion of magnets to create rotational motion. These forces therefore make the motor spin. The rotor uses magnets to achieve this motion. All of this takes place in a tiny space and can be much smaller than you might think. Connecting a power source, either from the mains or a battery, will cause the motor to start creating motion and therefore spinning.
As the motor spins around, it will transfer power from the battery to the commutator via tiny nylon brushes. The axle of the motor holds the rotor and commutator in place. The rotor or what’s called an armature will hold a set of magnets, in some cases three. That’s one field magnet and two permanent magnets. This field magnet is an important part of the motor and how it works.
An electromagnet is an important part of any motor. Electromagnets are created by wrapping wire (often copper) around a piece of iron and connecting it to a power source. This would make the iron magnetic only when the power is connected or turned on.
The electromagnet can then have an axle put through the middle, and can be placed inside a standard horseshoe magnet. When the power is switched on, the north and south poles of the electromagnet would repeal against the opposite poles on the horseshoe magnet. This would cause the nail or magnet to spin about halfway around and then stop. That’s because the half-turn is created by the magnets repelling each other to a certain point where the magnetism is the same.
So electric motors need a bit of additional technology in order to make the motor go around continuously. This is achieved by flipping the field of the electromagnet the instance the half-turn is complete. This makes the magnet do another half-turn and therefore a will have completed a total of one full turn. Flipping the field of the electromagnet is achieved by changing the flow of electrons down the wire, which is done by flipping the battery over. When flipping the field at the right precise moment, the motor spins freely and continuously.
Because electric motors can’t really be using nails, an armature is used instead. This is an electromagnet that has been made by coiling lots of thin wire around a core of metal.
This armature will have an axle which is connected to a commutator. The commutator is normally two plates that provide connections to the electromagnetic coil. The electromagnetic field is flipped because of the commutator and some brushes.
The touch points of the commutator are normally connected to the axle and allowed to spin with the magnet. There will also be some brushes which are either carbon or metal and touch the points of the commutator. All of these functions and parts together make an electric motor. The armature will go through a horizontal position and then the poles will flip. The north pole of the magnet will remain above the axle so that it can repel the field of the other magnet’s north pole and attract the south one.
By taking apart one of the many electric motors that are around your home, you will be able to see some of these pieces and functions in more detail. Be careful to make sure the motor isn’t running or connected to mains power while doing this. Make sure it isn’t something important in case you can’t put it back together.
There should be two permanent magnets in your motor, along with a commutator, some brushes, and an electromagnet.
While we’ve talked about two poles in the rotor to make the process a bit easier to understand, many will actually have three poles. That’s because this will make the motor work a bit better and will help the balance points of the electromagnet as well as making sure the motor doesn’t get stuck. Also, two pole rotors can short out a battery when the field is flipped whereas three poles will fix this issue.
But you can actually have any number of poles if you’ve got a much bigger electric motor. Two and three pole rotors are more common for simple electronic motors, but you can have much bigger ones with multiple poles.
Still not sure how common these motors are? They’re almost everywhere. Your blender, automatic can opener, tape deck or hi-fi, oven clock, microwave oven fan and fridge should all have their own electronic motors that use some of the science explained in this article. Have a look around your home to find a few more examples of electronic motors. Now you actually know a bit more about how they work so understand a bit more about the process. Make sure you know what you’re looking for if you have to change your motor or have them repaired.