Induction motor (1 Viewer)

[joesmith1975]

i dont understand the induction ac motor

please help , thanks

 

[helper]

Try
http://www.phys.unsw.edu.au/~jw/HSCmotors.html#Inductionmotors

 

[NightShadow]

the beauty of the induction motor is that there is no contact between the rotor and the stator coils (notices how in the induction motor the coils are in the stator, thenon moving bit)

now how does it work?!? by the principle of induction and lenz's law...
the stator coils are arranged in such a way with a microprocessor computer... that CURRENT flows through in such a way that it generates a ROTATING MAGNETIC FIELD around the rotor.

How does this affect the rotor? - you remember the transformer? how one coil can induce current and on another coil?
SAME HERE - the stator coils induce Current in the rotor coils


BUT by lenz's law... things dont like to be changed do they? (change in magnetic magnetic flux) - hence current flows in the rotor in a such a way to create a magnetic field that OPPOSES the CHANGING MAGNETIC FIELD OF THE STATOR

However as it does so.. due to the interaction of the magnetic fields...the rotor rotates along with the rotating magnetic field of the stator <---- IMPORTANT TO UNDERSTAND - remember the experiment with the magnet and the aluminium foil in a spike? you rotate to the magnet around the al foil.. and the al foil spins?

SIMILARLY - as the rotating magnetic field moves away... the rotor goes HEY! where'd my magnetic flux go!!! so it tries to create a magnetic field to replaced this change in flux.
e.g. suppose we're standing face to face...yes..hello... now you move to the left.... I am not happy at all... so what can i do to get you back in front of me.. i also move to the left

AHHHH i hear you say! thats why the rotor moves with the stator field

that is the basis of an induction motor


sorry but its hard to explain without diagram.. hope that helped

 

[I M J O S H]

^ What he said

 

[treepeep]

Extremenly impressive way of explaining it, NightShadow... o_o...

 

[Forbidden.]

How does an induction cooktop work ?

 

[P_Dilemma]

How does an induction cooktop work ?

It induces eddy currents in the pot that sits on the cooktop, producing heat, enough to boil your favourite water to cook your favourite instant noodles.

-P_D

 

[sinist4]

^ it induces eddy currents because of the AC current isnt it, and not Dc rite... im not sure

 

[alcalder]

Exactly. Only a Changing current can induce a magnetic field to then induce eddy currents.

 

[Lions_Fist]

It induces eddy currents in the pot that sits on the cooktop, producing heat, enough to boil your favourite water to cook your favourite instant noodles.

-P_D

Mmm I dunno, I don't really use my favourite water to cool noodles. I keep that for the good stuffs