The principle of electric motors work

The principle of electric motors work

Electricity can be transformed into mechanical energy by electric motors. This change is obtained by converting electrical energy into magnetic, and magnetic can cause movement. We already know that: the poles of magnets repel namesake and the poles are not namesake, of attraction. So we can get the movement if we put a magnet on a shaft that can spin, and another magnet in a fixed position.

Fig. Magnet rotates on its axis, if placed between the magnetic field.

Bar magnet rotates on its axis until the poles close to U S poles of permanent magnets and S poles of a magnet that rotates on its axis will be close to U of the magnetic poles are fixed. Magnets that can be called a rotor or rotating armature and rotating magnet that is not called a Stator.
Magnet on the stator kutub0kutubnya can change by changing the electrical current from positive to negative in electro magnetic.

Fig. By changing the flow of electricity in the stator, the magnetic field will also change and cause the rotor to rotate on its axis.

When the rotor in the upright position, the rotor poles of U of S attracted by the poles of the stator, as well as S of the rotor poles pulled by U of stator poles, thus setting the rotor to rotate and the rotor reaches a flat position, the electrical current will switch from positive to negative and the polarity of the stator also changed as well so that the polar-kutbnya changed, then the U of rotor poles approach the stator poles of U, they will repel each other, until the rotor back kekedudukan up, then approached the other poles. At that time the current changed again and the poles are also re-changed, so that the rotor can be kept rotating continuously.
The number of round 2 pole electric motors can be explained as follows:
1 cycle occurs in two changes: the positive and negative. In an electric 50 Hz (50 cycle per second) there are positive changes and 50 times 50 times negative, or 100 times the change in 1 second. With 100 times the change means that the motor will rotate 50 times in 1 minute so the motor will turn 50 x 60 = 3000 revolutions per minute (RPM).
Motor with 2 poles has become very popular in hermatik motors for refrigerators. In the motor has 4 poles, the amount of rotation will be lower, and the principle is similar to the 2 pole motor.
In the 4 pole motors, 4 takes 1 round or 2 cycles of change, so for 50 cycles in 1 second (50 Hz) will rotate as many as 25 times in 1 minute to 25 x 60 = 1500 RPM.
In the electric motor is usually no slip ± 4% of the ideal number of revolutions, to 1500 RPM is only 1440 RPM.

Motor speed can be explained by the following formula:

n = 120 x f
P


Where:

N = Number of rounds permenit (RPM)
F = Number of frequency (cycle)
P = Number of poles on the stator, a minimum of 2 and is always even.
120 = Every minute there are 60 seconds x times the change in cycle 1.