Single phase electric motor unit is only one winding, the rotor can be the squirrel-cage type. When the single-phase sinusoidal current during the entire stator windings, the motor will provide an alternating magnetic field, the magnetic field strength and direction of change at any time intercropping sine law, nonetheless spatial orientation is fixed, just what are the alternating magnetic field is pulsating magnetic field. The alternating magnetic field pulse tend to be decomposed into two that have the same speed, direction of rotation with the rotating magnetic field opposite family, after the rotor is stationary, each of those rotating magnetic field while in the rotor produce two equal and opposite torque, making the synthesis torque is zero, so that the motor can not rotate. While we use force in making the motor to rotate in one direction (eg clockwise rotation), to obtain clockwise rotation with the rotor as well as rotating magnetic field, magnetic field lines concerned with the cutting movement is small; counterclockwise rotation on the rotor and rotating magnetic field concerned with the larger magnetic field lines cutting exercise. This will break the total amount, package deal generated mainly because of the rotor on the electromagnetic torque won't be zero, the rotor will spin up up the drive direction.
 For single phase electric motor can automatically rotate up, worm reducer motor we can easily fabric such as a stator winding, starting winding and main winding 90 degrees difference in space, starting winding connected in series towards a suitable capacitor, together with the main winding current with the approximation with the phase difference of 90 degrees, the so-called split-phase theory. This difference in time, two 90-degree power flow in the two 90-degree difference at the space of winding will produce in space (two phase) rotating magnetic field, on the rotating magnetic field, the rotor will automatically start, start and right after the rise to the certain speed when attached with the rotor on a centrifugal switch and other automatic control device to disconnect first winding during normal operation simply primary winding work. Therefore, the starting winding can be short work. However, frequently, starting winding shouldn't disconnect, we know this as motor is really a single-phase motor, to enhance the direction of rotation, can change the position of the capacitor in series to obtain.
 Through the single phase motor unit, the rotating magnetic field produced another way regarded as shaded pole method, aka single-phase shaded pole motor. Salient-pole motor stator product of used, there's two poles and four poles two. Each pole inside of the all-pole top of the open 1/3--1/4 a groove, the pole is split into two parts, in a small region of the package on top of a short-circuit copper ring, since this perhaps the pole wall space very much the same, Tend to be shaded pole motor. Single-phase winding takes hold the entire pole, each pole of an coil is during series connection to make the polarity really should be pursued by N, S, N, S arrangement. Whenever the stator windings are energized, area of the magnetic flux generated around the magnetic poles, as outlined by Lenz's law, that your main magnetic flux through your short circuit copper ring around the copper ring to generate a phase lag of 90 degrees concerning the induced current, the present day generated in the magnetic on the phase lag can also be the popular flux, chain hoist its role in addition to the motor start winding capacitance corresponding to the motor rotating the rotating magnetic field generated up.