What is the working principle of a motor?

What is the working principle of a motor?

The principle of an electric motor is based on the current carrying conductor which produces magnetic field around it. A current carrying conductor is placed perpendicular to the magnetic field so that it experiences a force.

What is an electric motor state its principle?

Electric motor: An electric motor is a device which converts the electrical energy into the mechanical energy. Principle: An electric motor (dc motor) works on the principle that when an electric current is passed through a conductor placed normally in a magnetic field.

What is the working principle of an electric motor explain the function of three parts of an electric motor?

Commutator: It is the rotating interface of the armature coil with a stationary circuit. Field Magnet: The magnetic field helps to produce a torque on the rotating armature coil by virtue of Fleming’s left-hand rule. Armature Core: Holds the armature coil in place and provides mechanical support.

What is electric motor explain its principle construction working and its uses?

The principle of the electric motor is based on the fact that a current carrying conductor produces a magnetic field around it. A current carrying conductor placed perpendicular to magnetic field experiences a force.

What is electric motor explain with diagram?

Electric motor: A motor is a device which converts electrical energy into mechanical energy. Principle of motor : A motor works on the principle that when a rectangular coil is placed in a magnetic field and current is passed through it. Whereas the force on the side CD of the coil is in the upward direction.

What is the role of commutator?

The commutator assures that the current from the generator always flows in one direction. On DC and most AC motors the purpose of the commutator is to insure that the current flowing through the rotor windings is always in the same direction, and the proper coil on the rotor is energized in respect to the field coils.

What is the difference between armature and commutator?

An armature is a combination of the winding, commutator, brushes, and ball bearings….What is Commutator?

Armature	Commutator
It gives current from the armature core to commutator	It converts the alternating power to direct power and vice-versa

What is difference between commutator and slip rings?

Physically, a slip ring is a continuous ring, whereas a commutator is segmented. Functionally, slip rings provide a continuous transfer of power, signals, or data. Commutators, on the other hand, are used in DC motors to reverse the polarity of current in the armature windings.

Can commutator convert AC to DC?

A commutator in a DC Machine has alternate bands of Copper and mica. Now when the armature starts to rotate by an external force (in DC Generator), the coils situated in the armature also rotate. The coils are shorted via brush segment with alternate change in influence of poles.

What is the other name of commutator?

Hyponym for Commutator: electric switch, electrical switch, switch.

Why is a commutator used in a motor?

Commutators are used in direct current (DC) machines: dynamos (DC generators) and many DC motors as well as universal motors. In a motor the commutator applies electric current to the windings. By reversing the current direction in the rotating windings each half turn, a steady rotating force (torque) is produced.

What are the similarities and differences between electric motor and generator?

The motor and the generator are almost similar from the construction point of view, as both have stator and rotor. The main difference between the two is that the Motor is an electric device which converts electrical energy into mechanical energy. The generator is vice versa of that motor.

Why are brushes used in DC motors?

They can either be graphite or precious metal brushes which have electrical motor connections. To supply power to the rotor we put in place a brush system and each of the brushes have a direct voltage symbol (+/-). The brushes are connected to the commutator bars which allows the current to flow into the winding.

Why does an AC motor not need a commutator?

The main purpose of commutator is only to convert Ac to DC or vice versa, But in case of alternaters Commutator is not required because output will be AC only not DC. In case of DC generators Generation is AC so by using commutator will convert the AC to DC.

Can a DC motor run on AC?

The AC series motor you describe is a universal motor, and will work fine on DC. The speed characteristics will be a little different, since when running on AC there’s a significant reactive drop in the field windings that reduces the available driving emf.

What is the role of commutator in AC commutator motor?

A commutator is a moving part of a rotary electrical switch in certain types of electric motors and electrical generators that periodically reverses the current direction between the rotor and the external circuit. As the shaft rotates, the commutator reverses the flow of current in a winding.

Why are carbon brushes used in AC generators?

A carbon brush is a sliding contact used to transmit electrical current from a static to a rotating part in a motor or generator, and, as regards DC machines, ensuring a spark-free commutation.

Why do motors have brushes?

The function of the brushes is to conduct electricity to the individual segments as they rotate from brush to brush. This allows the motor to turn in one direction at a speed determined by the number of windings in the armature.

Why do we prefer carbon brushes than copper in AC generator?

Carbon has a very high melting point (~3500degC) compared with other conductors. Brushes made with copper or steel would wear out faster because of factors including: 1) The melted metal will break away from, or even be vaporized, leaving the brush with less material to do its job.

What are the advantages of carbon brushes?

5 most advantages of Carbon Brushes

1. High Melting Point. The carbon metal is generally having high melting point compared to copper as well as other metal.
2. Soft metal. The carbon brush is usually very soft metal compared to copper.
3. Negative temperature co-efficient. The carbon brush is having negative temperature co-efficient.
4. Shape adopting.
5. Self lubricating.

How do carbon brushes work?

Simply put, carbon brushes reduce the damage to the motor. The block of carbon, referred to as a brush, carries a current back and forth from the stationary parts of a motor to the moving parts. These brushes also help transmit electricity from outside the motor to the mid part, or spinning area of the motor.

How do I know if my carbon brushes need replacing?

As a general rule, if either brush has worn to about a quarter inch long, it is time to replace it. If the carbon (a brush is essentially a carbon block with a metal spring tail) shows any signs of breakage, crumbling, or burning, the brush needs replacing.

Do AC motors use brushes?

AC induction motors have no brushes and have a much longer life expectancy. DC motor speed is controlled by varying the armature current, while AC motor speed control is achieved by varying the frequency of the alternating current, often with a variable frequency drive(VFD).

How do I know if my electric motor brushes are bad?

If there’s a banging sound inside the tool’s motor when it runs, then it’s probably a brush. It could also be a bad armature, but if that is the case then it’s most likely that the brushes will have to be replaced anyway. As the armature spins, either kind of damage will make the brushes bounce off of the commutator.

How do you test electric motor brushes?

How to Test Motor Brushes

1. Turn off the power to your electric motor, before attempting to test the brushes.
2. Use a pair of long-nosed pliers and remove the retaining clip that holds the one of the brushes in place.
3. Check the length of the carbon brush against the size of the brush holder.
4. Repeat the process on the other brush.

What is the most common cause of motor failure?

The most common cause of motor failure, and arguably the most difficult to overcome, is low resistance. Low resistance is caused by the degradation of the insulation of the windings due to conditions such as overheating, corrosion, or physical damage.

How long do motor brushes last?

As an estimate, 7,500 hours brush life is normal for general purpose, medium horsepower DC motors with good commutator film with commutator surface speeds in the range of 2,500 to 4,000 feet per minute. The minimum life might be 2,000 to 5,000 hours with 10,000 hours being about maximum.

How can a motor be made more powerful?

Motor can be made more powerful by winding the coil on a soft iron core of by increasing the number of turns of the coil.