Introduction to Motor

Electric motors are everywhere! In your house, almost every mechanical movement that you simply see around you is caused by an AC (alternating current) or DC (direct current) motor. 

A motor converts electricity into energy. it’s estimated that almost half the world’s energy consumption is consumed by motors. Therefore, increasing motor efficiency is predicted to possess a big impact on the worldwide energy crisis. Here we’ll explain the operating principle of motors, beginning with the fundamentals. 

How Electric Motors Work

When you put all of those parts together, what you’ve got maybe a complete electric motor:

In this figure, the armature winding has been overlooked in order that it’s easier to ascertain the commutator in action. The key thing to note is that because the armature passes through the horizontal position, the poles of the electromagnet flip. due to the flip, the North Pole of the electromagnet is usually above the axle so it can repel the sector magnet’s the North Pole and attract the sector magnet’s South Pole.

If you ever have the prospect to require apart from the little motor, you’ll find that it contains equivalent pieces described above: two small permanent magnets, a commutator, two brushes, and an electromagnet made by winding wire around a bit of metal. nearly always, however, the rotor will have three poles instead of the 2 poles as shown during this article. There are two good reasons for a motor to possess three poles:

Different Types of Motor

Motors that operate through rotation by receiving power when current flows within a magnetic flux are common. However, a good range of motor types exists, including ones that operate through linear motion.

Motors are broadly classified by the sort of drive power used (source): DC.

They can even be further divided by the rotational principle, as shown within the chart below.

  • Brushed Motor: This is the broadest class of Motor. as DC motor on is achieved through current switching when an electrode called a ‘Brush’ (stator side). sequentially contacts a commutator (armature side). This type of motor produces a magnetic flux during a wound rotor (the part that rotates) by passing an electrical current through a commutator and carbon brush assembly, hence the term “Brushed”. The stators (the stationary part) magnetic flux is produced by using either a wound stator field coil or by permanent magnets. Generally, brushed DC motors are cheap, small and simply controlled.  
  • Brushless Motor: in this sort of motor, the operation is performed by switching current electrically employing a switching element, like a transistor, rather than a brush and commutator. This type of motor produces a magnetic flux within the rotor by using permanent magnets attached thereto and commutation is achieved electronically. they’re generally smaller but costlier than conventional brushed type DC motors because they use “Hall effect” switches within the stator to supply the specified stator field rotational sequence but they need better torque/speed characteristics, are more efficient and have an extended operating life than equivalent brushed types.  
  • Servo Motor: a motor that operates in sync with the heartbeat power also knows as a pulse motor. this of the motor is characterized by easy, accurate positioning operation.
    This type of motor is essentially a brushed DC motor with some sort of positional feedback control connected to the rotor head . they’re connected to and controlled by a PWM type controller and are mainly utilized in positional control systems and radio-controlled models.

Inside an Electric Motor

An el­ectric motor is all about magnets and magnetism: A motor uses magnets to make the motion. If you’ve got ever played with magnets you recognize about the elemental law of all magnets: Opposites attract and likes repel. So if you’ve got two bar magnets with their ends marked “north” and “south,” then the north end of 1 magnet will attract the south end of the opposite.

On the opposite hand, the north end of 1 magnet will repel the north end of the opposite (and similarly, south will repel south). Inside an electrical motor, these attracting and repelling forces create rotational motion. ­

In the above diagram, you’ll see two magnets within the motor: The armature (or rotor) is an electromagnet, while the sector magnet may be a static magnet (the magnet might be an electromagnet also, but in most small motors it is not so as to save lots of power).