Electric motor

 

Electric motor                                                     

 

An electric motor is rotating machine or device that converts the electrical energy to mechanical energy.



 

An electric motor is consists of a rectangular coil ABCD of insulated copper wire. The coil is placed between the two poles of magnetic field. The rectangular coil of the arms AB and CD are kept in such a manner that both rms are perpendicular to the direction of the magnetic field. The ends of the coil are connected to the two halves P and Q of a split ring. The inner side of the halves are insulated and attached to the axle. The external conducting edges of P and Q touch the two conducting stationary brushes X and Y respectively.

 

Working :--

 

A source of battery is used to enter  the current in the coil through conducting brushes X and flows back to the battery through brush Y.

Now , the current in the arms of the rectangular coil AB is flowing from A to B

And the  current in the arms of the coil CD is flowing from C to D. It means it is opposite direction of the current through the arms of the coil AB .

On applying the fleming’s left hand rule for the direction of the force on a current carrying conductor in a magnetic field.

Due to this , the force acting on arms AB pushes it downwards while the force acting on arms CD pushes it upwards.

Thus the coil and the axle O , mounted free to turn about an axis , rotate anti-clockwise.

After half rotation, Q ix contacted with brush X and P is contacted with Y.

Therefore , the current in the coil gets reversed and flow in the direction of the  DCBA.

A device that is used to reverse the flow of the direction of the flow of the  current in the circuit is known as the commutator.  

In the electric motor, the split rings behaves as commutator.

When the current is reversed , then the direction of the force acting on the both arm AB and CD is also reversed.

And now,  the arm AB of the coil that was pushed down in the earlier. And now it is pushed up .

And the arm CD of the coil that was pushed up in the earlier. And now it is pushed down.

Therefore , the coil and the axle rotate half a turn more in the same direction. the reversing of the current is repeated at each half rotation, giving rise to a continuous rotation of the coil and the axle.

And the soft iron core on which the coil is wound plus the coil ic called armature. This enhances  the power of the motor.

 


A simple electric motor has six parts:--

 

1.  Armature or rotor

2.  Commutator

3.  Brushes

4.  Axle

5.  Field magnet

6.  DC power supply or battery

 

1. Armature or rotor:--

                                        It is a component of the electric machine like electric motor or electric generator that carries alternating current (AC).the armature winding conduct AC on DC (direct current) machines  via a commutator action which periodically reverse current direction ) or due to electronic commutation (like in the brushless DC motors).

 

2.  Commutator:--

                                A device that is used to reverse the flow of the direction of the flow of the  current in the circuit is known as the commutator. In the electric motor, the split rings behaves as commutator.

 

3. Brushes:--

                       Brushes are the electrical contact which produce the electric current between the stationary wires and moving parts most commonly in a rotating shaft.

 

4. Axle:--

            the two halves of the ring have a resistive coating in the inner of the their surfaces. And they are tightly fitted inti the axle. And the main function of the Axle is used to rotate with the coil.

 

 

 

5.  Field magnet:--

                            the armature coil is placed between the the poles (N or S) of strong horse shoe magnet which provides strong magnetic field.

 

6. Battery or DC power supply :--

                                                           Battery supplies current to the armature coil. It is connected with the carbon brushes.

 

 

 

Comments

Post a Comment

Popular posts from this blog

METAL And Chemical Properties of metals

  METAL Metal is a element that has metallic bond and have positive ions or cations. Metal is a lattice of positive ions that are surrounded by the cloud of the electrons. In the pure state, metal have a shining surface. This properties are called metallic luster . Here, metals are generally hard. Metals are malleable, because they can be hammered into thin sheets. This property is called as malleability . Metals are ductile it means they can be drawn into wires. The ability of the metals to be drawn into thin wires is called as ductility . For example:--   gold is most ductile metal. Due to the properties of the ductility and malleability, metals can be given in different shapes as per their needs. Metals are opaque Metals are lustrous elements that are good conductor of heat and electricity. Metals are denser than the other substances. Metals are good conductor of heat. For example :-- silver and copper. Lead and mercury are poor conductors of heat. ...
Read more

Food chains and webs, Tropic levels

Image
Food chains and webs   Food chain is the sequence of organisms in which nutrients and energy is transferred in the form of food from one organism to another organisms. Food chain is the possible pathway in which nutrients and energy is transferred through an ecosystem. A food chain is the linear network of links in which a food web is starting from producers organisms and is ending at decomposers.   A food chain shows a series or organisms taking part at various biotic level. Each steps or levels of the food chain forms a tropic level . The tropic level of an organisms is the position it occupies in a food web. Organisms in food chain are grouped into categories are known as trophic levels. Tropic levels are divided into various levels:--   Producers:--                      The producers or the autotrophs are the first trophic level.   All green plant...
Read more

Eco system

                            Eco system   Eco system is a complex relationship among all organisms such as plants , animals , microorganisms and the human beings and the physical surroundings. And they interact with each other and maintain a balance in environment. An ecosystem is a biological community   of interacting organisms   and their physical environment with non-living organisms form an ecosystem. Thus, an eco system consists of biotic and abiotic components A biotic   component comprising all living organisms. A abiotic components comprising physical factors like temperature, rainfall, wind soil, minerals, etc.   A garden is an eco system In a garden, when we go to the garden, we see that there is different types of plants like as grasses, trees, flower plants like rose jasmine, etc and animals like frogs...
Read more