Electric motors
What is an electric motor?
A device that converts the electric energy into mechanical energy is known as an electronic motor . They have become a part of the human life and are found everywhere . Almost all the household appliance made today have a motor like a fan, washing machine, pumps and refrigerators. The working of an electronic motor is based upon a simple fundamental principle that there exists a mechanical force on any current carrying wire that is kept within a mechanical field. The rotating part of the electronic motors are called rotor and the stationary part is known as the stator . As a current is passed through the stator a torque is generated that makes the rotor to rotate .
A brief history of electronic motors
The principle of the conversion of the electrical energy into mechanical energy was first demonstrated by a British scientist named Michael Faraday way back in the 1821 . His experiment consisted of a free hanging wire that was dipped into mercury and a magnet that was placed into the mercury . There after when a current was passed through the wire it started rotating around the magnet . The first commutator type direct flow electric motor was made by William Sturgeon in 1832 who was also a British scientist . After the invention of William an American named Thomas Davenport made the first commutator type electronic motor that was for commercial use. All the above motors invented were not successful in the market because of the high cost involved in it. The modern DC motors that are used today were invented by accident in 1873 by Zenobe Gramme .
Types of electric motors
The motors can be divided broadly into two categories . The first one is the AC i.e. alternating current motor and the second one is the DC i .e. direct current motor.
DC motors: These are the motors that are designed to run on the direct current supply and mostly compromise of the brushed and the brushless DC motors. Brushed DC motors are designed to generate movement in the rotor that is wounded within a magnet stator. The brushed DC motors had many disadvantages and thus to eliminate them a brushless motor was invented . This motors rotating switch was replaced by an external electronic switch which was synchronized with the rotors position . This thing increased the efficiency of the motor to a great extent .
Universal motors: These are the motors that can be easily used with the supply of both DC and the AC current . The basic advantage of the universal motors is that it provides a high starting torque and is very compact in design. The disadvantages associated with the universal motors are that the maintenance costs are very high along with the short life of the commutator.
AC motors: The motors using the alternating current are better known as the AC motors and mainly consist of two basic components. An outside stator that has coils is supplied with AC current to produce a rotating magnetic field and the second inside rotor attached to the output shaftOther Links
