- An electric motor is a device that uses electrical energy to produce mechanical energy. In other words, it makes things move by using electricity. Devices that are powered by batteries or plugged into an electric socket--from cars to sewing machines to watches--usually contain an electric motor.
- At the heart of an electric motor is the electromagnet. An electromagnet is based on the idea that when electricity flows through a coiled wire, a magnetic field forms. When a piece of metal is inserted through the center of the coil, the magnet field becomes even stronger. The coiled wire and the piece of metal together are called an electromagnet. Like all magnets, an electromagnet has a north pole and a south pole.
- The field magnet is a horseshoe-shaped magnet that curls around the electromagnet. Because of the properties of magnetism, the electromagnet will spin until its north pole is facing the field magnet's south pole and its south pole is facing the field magnet's north pole. This is the first step of the spinning motion that powers an electric motor. The next step is to find a way to make it spin indefinitely.
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There are two types of current used to power an electric motor: alternating current (AC) and direct current (DC) current. By definition, the direction of the current in AC alternates, which means that the magnetic field in an an electromagnet powered by AC will continually flip. This will cause the north and south poles on the electromagnet to switch places multiple times every second, which will cause the electromagnet to spin indefinitely.
DC does not alternate, so a commutator is used instead. A commutator artificially changes the direction of the current inside the electromagnet, which leads to the same effects as AC. Either way, the motor will spin indefinitely, converting the electrical energy into mechanical energy.
