The commutator is also attached to the axle. The commutator is simply a pair of plates attached to the axle. These plates provide the two connections for the coil of the electromagnet. The "flipping the electric field" part of an electric motor is accomplished by two parts: the commutator and the brushes. The diagram shows how the commutator in green and brushes in red work together to let current flow to the electromagnet, and also to flip the direction that the electrons are flowing at just the right moment.
The contacts of the commutator are attached to the axle of the electromagnet, so they spin with the magnet. The brushes are just two pieces of springy metal or carbon that make contact with the contacts of the commutator. The key is that as the rotor passes through the horizontal position, the poles of the electromagnet flip. Because of the flip, the north pole of the electromagnet is always above the axle so it can repel the stator's north pole and attract the stator's south pole.
Usually the rotor will have three poles rather than the two poles as shown in this article. There are two good reasons for a motor to have three poles:. It is possible to have any number of poles, depending on the size of the motor and what it needs to do. Now, we're going to look at the AC motor. AC motors use alternating current instead of direct current.
It shares many parts with a DC motor, and it still relies on electromagnetism and flipping magnetic fields to generate mechanical power. The winding of the stator in an AC motor kind of does the job of the rotor of a DC motor. In this case, it's a ring of electromagnets that are paired up and energized in sequence, which creates the rotating magnetic field.
You'll remember that the rotor in a DC motor is hooked up to the battery. But the rotor in an AC motor does not have any direct connection to a power source. Nor does it have brushes. Instead, it often uses something called a squirrel cage. You read that right. The squirrel cage in an AC motor is a set of rotor bars connected to two rings, one at either end. It's kind of like something a caged mouse or squirrel would run inside. The squirrel cage rotor goes inside the stator.
When AC power is sent through the stator, it creates an electromagnetic field. The bars in the squirrel cage rotor are conductors, so they respond to the flipping of the stator's poles. That's how the rotor rotates, which creates its own magnetic field. The key to an AC induction motor, where the field of the rotor is induced by the field of the stator, is that the rotor is always trying to catch up.
It's always looking for stasis, so it's rotating to find that steady state. But the electromagnetic field produced by the stator using AC power is always going to be a little faster than the rotor's field.
The spin of the rotor is creating the torque needed to create mechanical power to turn the wheels of a car or the whirr of a fan. Some AC motors use a wound rotor, which is wrapped with wire instead of being a squirrel cage. Electric motors affect almost every aspect of daily life.
They can be found in homes, schools and even in cars. Electric motors A coil of wire carrying a current in a magnetic field experiences a force that tends to make it rotate. However, since you have stripped half the wire, no current will flow during the time the coil is inverted. This is so that we don't end up with a force in the opposite direction making the coil reverse instead of continue.
Provided the initial push due to the field is strong enough, the coil will flip past degrees, making a complete rotation, toward the end of which current flows in such a way that a force causes it to make another rotation just as before.
If everything is balanced well enough, the motor should rotate fairly quickly and for a long time. The armature is the power-producing part of the motor. It may be located on the rotor rotating part or the stator stationary part. The armature consists of coils of wire that interact with the magnetic field when current passes through. In our homemade motor, the coil was the armature and rotor and the paperclips served as the stator.
Brushes allow for current to be transferred to the rotor as it rotates. In our homemade motor, the contact point of the paper clips and the copper wire served the same purpose.
A commutator serves to periodically reverse the current direction. This is needed in a direct current, or DC motor, but not usually in an alternating current, or AC motor because the current already changes direction.
A field magnet or field coils electromagnets create the necessary magnetic field. The axle is a rod-shaped piece aligned with the rotor's rotation axis such that it rotates along with the rotor. How to Make an Alternator.
How to Make a Simple Generator. Information for Kids About Electromagnets. Simple Electrical Projects. How to Build a Model Electricity Generator. How to Make an Electric Fan. How Does a Magneto Work? How to Make a Negative Charge Magnet. How to Make a Tesla Coil. How to Build a Gyroscope.
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