A shaded-pole motor is a type of AC

Alternating current

In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....

  single-phase

Single-phase electric power

In electrical engineering, single-phase electric power refers to the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors...

 induction motor

Induction motor

An induction or asynchronous motor is a type of AC motor where power is supplied to the rotor by means of electromagnetic induction. These motors are widely used in industrial drives, particularly polyphase induction motors, because they are robust and have no brushes...

. It is basically a small squirrel cage motor in which the auxiliary winding is composed of a copper ring surrounding a portion of each pole. This auxiliary winding is called a shading coil. Currents in this coil delay the phase

Phase (waves)

Phase in waves is the fraction of a wave cycle which has elapsed relative to an arbitrary point.-Formula:The phase of an oscillation or wave refers to a sinusoidal function such as the following:...

 of magnetic flux

Magnetic flux

Magnetic flux , is a measure of the amount of magnetic B field passing through a given surface . The SI unit of magnetic flux is the weber...

 for that pole (a shaded pole) enough to provide a rotating magnetic field

Rotating magnetic field

A rotating magnetic field is a magnetic field which changes direction at a constant angular rate. This is a key principle in the operation of the alternating-current motor. Nikola Tesla claimed in his autobiography that he identified the concept of the rotating magnetic field in 1882. In 1885,...

. The direction of rotation is from the unshaded side to the shaded (ring) side of the pole.