e-phase AC induction motors
　　单相交流感应电机
　　Three-phase motors inherently produce a rotating magnetic field. However, when only single-phase power is available, the rotating magnetic field must be produced using other means. Several methods are commonly used:
　　三相电机会自动产生旋转的磁场。但是，当供电系统为单相时，则需要用其他的方法来产生旋转磁场。通常用以下几种方法：
　　[ ] Shaded-pole motor
　　A common single-phase motor is the shaded-pole motor, which is used in devices requiring low starting torque, such as electric fans or other small household appliances. In this motor, small single-turn copper "shading coils" create the moving magnetic field. Part of each pole is encircled by a copper coil or strap; the induced current in the strap opposes the change of flux through the coil (Lenz's Law), so that the maximum field intensity moves across the pole face on each cycle, thus producing a low level rotating magnetic field which is large enough to turn both the rotor and its attached load. As the rotor accelerates the torque builds up to its full level as the principal (rotationally stationary) magnetic field is rotating relative to the rotating rotor. Such motors are difficult to reverse without significant internal alterations.
　　[_]蔽极式电机
　　通常所见的单相电机都是蔽极式电机，一般用于启动力矩小的设备中，比如电风扇和其他的小型家用电器中。在这种电机中，小的单级旋转隐蔽铜线圈会产生转动的磁场。每个极的部分都被铜线圈或铜带包围住；为了阻止线圈中的电流变化（楞次定律）铜带中就会产生感应电流，以便每个周期最大场强都能越过极面，从而产生一个足够大的低级转动磁场来传动转子以及它上面的负载。随着转子增加它的扭矩到最大，原（固定转动的）磁场就会随着转子的转动而转动。这些电机很难反转，除非内在结构有所变化。
　　[ ] Split-phase induction motor
　　[_]分相感应电机
　　Another common single-phase AC motor is the split-phase induction motor, commonly used in major appliances such as washing machines and clothes dryers. Compared to the shaded pole motor, these motors can generally provide much greater starting torque by using a special startup winding in conjunction with a centrifugal switch.
　　另外一种常见的单相交流电机就是分相感应电机，通常用于像洗衣机和干衣机这样的大型家用电器中。与蔽极式电机相比，这些电机通过将启动绕组和离心开关连接在一起通常可以提供很大的启动力矩。
　　In the split-phase motor, the startup winding is designed with a higher resistance than the running winding. This creates an LR circuit which slightly shifts the phase of the current in the startup winding. When the motor is starting, the startup winding is connected to the power source via a set of spring-loaded contacts pressed upon by the not-yet-rotating centrifugal switch. The starting winding is wound with fewer turns of smaller wire than the main winding, so it has a lower inductance (L) and higher resistance (R). The lower L/R ratio creates a small phase shift, not more than about 30 degrees, between the flux due to the main winding and the flux of the starting winding. The starting direction of rotation may be reversed simply by exchanging the connections of the startup winding relative to the running winding..
　　在分相式电机里，设计启动绕组的电阻要比运行绕组的电阻大。这样就会产生一个LR电路，这个电路会轻微改变启动绕组里的电流的相位。当电机在启动时，启动绕组通过一组上面压着没有转动的离心开关的弹簧连接在电源上。缠绕启动绕组线比主绕组所用的线要细而且少几圈，所以它是高电阻低电感。电感与电阻的低比率会产生一个不超过30度的小相移，这个相移是由主绕组决定的磁力线和由启动绕组决定的磁力线。可以通过改变启动绕组和运行绕组的连接来轻易改变启动时的旋转方向。
　　The phase of the magnetic field in this startup winding is shifted from the phase of the mains power, allowing the creation of a moving magnetic field which starts the motor. Once the motor reaches near design operating speed, the centrifugal switch activates, opening the contacts and disconnecting the startup winding from the power source. The motor then operates solely on the running winding. The starting winding must be disconnected since it would increase the losses in the motor.
　　启动绕组磁场的相位随着电网的相位变化而变化，从而产生一个启动电机的旋转磁场。一旦电机达到接近设计运行转速，离心开关开始动作，关断启动绕组与电网之间的连接。电机通过运行绕组运行。启动绕组必须被断开，因为它会增加电机的损耗。
　　[ ] Capacitor start motor
　　In a capacitor start motor, a starting capacitor is inserted in series with the startup winding, creating an LC circuit which is capable of a much greater phase shift (and so, a much greater starting torque). The capacitor naturally adds expense to such motors.
　　[_]电容启动电机
　　在电容启动电机，启动电容与启动绕组串连在一起，从而形成一个LC电路，这个电路有很好的相移（因此也有很好的启动扭矩）。这个电阻也会给电机增加成本。
　　[ ] Permanent split-capacitor motor
　　Another variation is the Permanent Split-Capacitor (PSC) motor (also known as a capacitor start and run motor). This motor operates similarly to the capacitor-start motor described above, but there is no centrifugal starting switch and the second winding is permanently connected to the power source. PSC motors are frequently used in air handlers, fans, and blowers and other cases where a variable speed is desired. By changing taps on the running winding but keeπng the load constant, the motor can be made to run at different speeds. Also provided all 6 winding connections are available separately, a 3 phase motor can be converted to a capacitor start and run motor by commoning two of the windings and connecting the third via a capacitor to act as a start winding.
　　[_]固定分相电容式电机
　　另外一种电机是固定分相电容式（PSC）电机（也就是电容式启动和运行电机）。这种电机的运行方式与上面描述的电容式启动电机类似，但它没有离心开关，所以它的二次绕组始终与电网连接在一起。PSC电机通常用在吹风机，电风扇，送风机和其他一些需要变速的场合。在负载不变的情况下通过改变运行绕组的信号来达到使电机运行在不同速度下的目的。所有的6绕组都分别连接，一个三相电机可以通过将两个绕组连接在一起其余一个绕组通过电容连接为启动绕组来转变成为一个电容启动运行电机。
　　[ ] Repulsion motor
　　Repulsion motors are wound-rotor single-phase AC motors that are similar to universal motors. In a repulsion motor, the armature brushes are shorted together rather than connected in series with the field. Several types of repulsion motors have been manufactured, but the repulsion-start induction-run (RS-IR) motor has been used most frequently. The RS-IR motor has a centrifugal switch that shorts all segments of the commutator so that the motor operates as an induction motor once it has been accelerated to full speed. RS-IR motors have been used to provide high starting torque per ampere under conditions of cold operating temperatures and poor source voltage regulation. Few repulsion motors of any type are sold as of 2005.
　　[_]推斥式电机
　　推斥式电机是绕线转子单相交流电机，它与交直流电机相似。在推斥式电机里，电枢与电刷短接在一起而不是和磁场串联在一起。已经有几种推斥式电机投入生产使用，但用的最多的还是推斥式启动感应运行（RS-IR）电机。RS-IR电机有一个离心开关将所有的换向器短接在一起，所以当它加速到全速时它就会以感应电机的方式运行。RS-IR曾用于在电机低温和低稳压每安培下提供大启动扭矩。在2005年几乎没有销售任何类型的推斥式电机。
　　[ ] Single-phase AC synchronous motors
　　Small single-phase AC motors can also be designed with magnetized rotors (or several variations on that idea). The rotors in these motors do not require any induced current so they do not slip backward against the mains frequency. Instead, they rotate synchronously with the mains frequency. Because of their highly accurate speed, such motors are usually used to power mechanical clocks, audio turntables, and tape drives; formerly they were also much used in accurate timing instruments such as strip-chart recorders or telescope drive mechanisms. The shaded-pole synchronous motor is one version.
　　Because inertia makes it difficult to instantly accelerate the rotor from stopped to synchronous speed, these motors normally require some sort of special feature to get started. Various designs use a small induction motor (which may share the same field coils and rotor as the synchronous motor) or a very light rotor with a one-way mechanism (to ensure that the rotor starts in the "forward" direction).
　　[_]单相交流同步电机
　　小型单相电机也可以被设计成磁化转子。这种电机中的转子不需要任何感应电机，所以他们不会低于主频。相反，他们会随着主频同步转动。因为他们的高精确转速，此类电机通常用在电力机械时钟，唱片机和录音机中；他们也用于像带状记录机和望远镜驱动机构这样需要精确时间的设备中。蔽极式同步电机就是其中的一种。
　　因为惯性的缘故，所以很难将转子从停止状态立即加速到同步转速。这类电机通常需要一些特殊的方法来启动。各种不同的设计用小型感应电机（它会和同步电机一样共用相同的励磁线圈和转子）或单向转速（保证转子启动时为正向转速）的非常轻的转子。
　　[ ] Electronically Commutated Motors
　　(a section needs to be written for ECM motors) ECM motors are increasingly being found in forced-air furnaces and HVAC systems to save on electricity costs as modern HVAC systems are running their fans for longer periods of time (duty cycle). The cost effectiveness of using ECM motors in HVAC systems is questionable, given that the repair (replacement) costs are likely to equal or exceed the savings realized by using such a motor.
　　[_]电子换相电机
　　ECM电机在强迫通风熔炉和为了节约用电的HVAC系统中用的越来越多，因为HVAC系统的风扇在白天运转时间很长。在HVAC系统中用ECM电机的成本效率还有待商榷，修理这种电机的费用几乎等于甚至超过了它省下的费用。
　　其他
　　单相电容运行电机一般主副相为并联，这时主副相电流在我们实际使用的负载范围内为90度左右，可以获得最佳性能；
　　而串联接法一般出现在变极调速的某极绕组中，这时在实际使用的负载范围内主副绕组基本角度一致，无法形成圆形磁场。