Simple AC Motors

J Pemberton

Best Website on This!

http://www.physclips.unsw.edu.au/jw/electricmotors.html

There are two main types

Synchronous- a magnet or current carrying coil moving due to a changing magnetic field.

Induction- a piece of metal in a changing magnetic field has currents set up in it which then experience a force.

Simplest AC Motor

To understand this we have to revise the field directions for solenoids.

Check you agree with the next few slides

Simple AC Motor- first part of cycle

N

SLook closely at the current directions, Do you agree with the field directions?

Simple AC Motor- Make your predictions for the second half of cycle

Simple AC Motor- Second half of cycle?

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S

The north pole will seek out the south poles of the solenoid and visa versa.

Simple AC Motor- Now with the magnet

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S

Which way will the magnet want to go?

Simple AC Motor- first part of cycle

N

S

Did you guess correctly?

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Now we’re back to the beginning.

N

S

Which way will the magnet want to go?

Simple AC Motor- An off we go!

N

S

Which way will the magnet want to go?

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Now we’re back to the beginning.

N

S

Which way will the magnet want to go?

Simple AC Motor- Now we’re back to the beginning.

N

S

Which way will the magnet want to go?

Simple AC Motor- Now we’re back to the beginning.

N

S

Which way will the magnet want to go?

Simple AC Motor- Now we’re back to the beginning.

N

S

Which way will the magnet want to go?

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

Simple AC Motor- Second half of cycle The field gets switched.

N

S

AC motors often have more than two solenoids

Simple AC Motor- four coils

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S

S N

Simple AC Motor- four coils

N

S

S N

Simple AC Motor- four coils

N

S

S N

Simple AC Motor- four coils

N

S

S N

Simple AC Motor- four coils

N S

S

N

Simple AC Motor- four coils

N S

S

N

Simple AC Motor- four coils

N S

S

N

Simple AC Motor- four coils

N S

S

N

Simple AC Motor- four coils

NS

S

N

Simple AC Motor- four coils

NS

S

N

Simple AC Motor- four coils

NS

S

N

Simple AC Motor- four coils

NS

S

N

N

S