Simple AC Motors J Pemberton

Best Website on This! icmotors.html icmotors.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 S Look 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? N S

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

Simple AC Motor- Now with the magnet N 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

N S

N S

Simple AC Motor- Now were 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

N S

N S

N S

Simple AC Motor- Now were back to the beginning. N S Which way will the magnet want to go?

Simple AC Motor- Now were back to the beginning. N S Which way will the magnet want to go?

Simple AC Motor- Now were back to the beginning. N S Which way will the magnet want to go?

Simple AC Motor- Now were 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

N S

N S

N S

N S

N S

N S

AC motors often have more than two solenoids

Simple AC Motor- four coils N S S N

N S S N

N S S N

N S S N

N S S N

N S S N

N S S N

N S S N

N S S N

N S S N

N S S N

N S S N

N S