Three basic type of dc motor?

Answer 1

hair dryer, cars ,lawnmower ,generator ,computer ,pool ,cleaner ,tv ,plane ,cell phone ,fans ,heaters ,remote contrl car ,boat

For DC:

Permanent magnet brush motor; (uses fixed magnets for stator fields); toys and automotive use

Shunt field motor; (field winding has many turns of fine wire in parallel with armature) small machines;

Series field motor; (field winding has few turns of heavy wire in series with armature); high speed, high torque;

Compound field motor; (has both series and shunt fields); large machinery, general purpose workhorses;

Brushless DC motors (use electronics to switch stator windings on and off, and have permanent magnet rotors) small fans and light loads.

For single phase AC:

Split Phase induction motor (2 different windings connected to supply, cage type rotor) low torque, general purpose;

Capacitor Start induction motor; (As per split phase, but with capacitor in series with starting winding) high starting torque, general purpose;

Capacitor start, Capacitor run induction motor; (as per capacitor start, but different capacitors used for starting and running) high starting and running torque, quietest running;

Shaded pole induction motor; (run winding and copper or aluminium ring around part of iron core of stator) small, cheap motors, low torque;

Universal motor; (as per series DC motor above) high torque, high speed, poor speed stability.

For 2 or 3 phase AC (star or delta connected)

Polyphase induction motor (2 or 3 identical windings on stator, cage rotor) general purpose;

Wound rotor induction motor (2 or 3 identical windings on stator, wound rotor connected in star to 3 sliprings and external resistance unit) very high starting torque, low starting current;

Synchronous motor; (standard stator, and wound rotor connected to DC supply for 'excitation' of rotor field) constant speed, power factor correction.

Answer 2

Electric Motors?

The 'AC' in AC motors stands for alternating current and indicates that these machines use an alternating current to provide power. An alternating current means that the electrons traveling along the conductor switch direction regularly, so that they flow first forwards and then backwards. AC electricity was first invented by Nikolas Teklas in the 1880s. AC electric motors can retain energy more efficiently than DC machines and they are also better able to transfer different amounts of power.

AC electric motors consist of two main parts: the external stator and the internal rotor. The stator is responsible for producing a rotating magnetic field which in turn produces the torque received by the rotor. There are two different categories of AC machines, the induction and the synchronous. Induction electric motors use an induced current to produce the magnetic field and will always runt at a slightly slower or faster speed than the supply frequency. Conversely, synchronous machines do not rely on an induced current and are able to run at exactly the same speed as the supply frequency.

Most AC machines use squirrel cage rotors, named for their resemblance to the exercise toy for rodents. These rotors have two ring shaped windings at either end with bars running along the length of the rotor. The squirrel cage rotors used in AC electric motors generally act as Transformers, acting to bring the rotor into synchronisation with the stator's field. As the mechanical load on the machine increases, the rotor also increases the power used.

Two type of electric motors:-

AC motors: These motors are driven by alternate current. You can find two main types of AC motors - Induction motor and Synchronous motor. Induction motor runs slightly slower than the supply frequency. It is named so because the magnetic field on the rotor of this device is created by an induced current.

DC motors: These motors can rotate exactly at the supply of the frequency or a sub-multiple of the supply frequency as they do not rely on induction. In this device, the magnetic field on the rotor is generated either by current delivered by the slip rings or by a permanent magnet.

Answer 3

Induction motors are used for loads of medium power, synchronous motors are for constant high-power loads because the power factor is easier to control.

Single-phase commutator motors are used when a high power-to-weight ratio is needed for short periods, as in a hoover.

Answer 4

Series DC Motor Shunt DC Motor

Compound DC Motor

Answer 5

1.Changeless magnet

2.Electromagnets associated in arrangement

3.Shunt

4.Compound

Answer 6

Series wound.

Parallel wound.

Compound wound, which has both series and parallel windings.

Answer 7

the three phase motors are basically of two kinds..

synchronous motors

and

induction motors

Answer 8

Mainly two types - Squirrel cage induction motor (SQIM) and slip ring induction motor. Application of slip ring type is limited to specific application, where as SQIM type is wide spread.

Answer 9

synchronous and induction motors