AC Motors

A AC motor is a electric motor which is powered by alternating current. AC motors can be divided into two groups single phase and three phase. Single phase AC is the common supply of a normal home, three phase power is used in factories. 

Induction

Induction motors use shorted wire loops on a rotating armature and obtain their torque from currents induced in these loops by the changing magnetic field produced in the stator (stationary) coils.

Cut away of AC motor

Universal Motor

The most common of the single AC motor is known as a universal motor, this is because this type of motor can run on DC as well. Cheap to make but very inefficient, it is mostly found in hand drills, mixers anything that needs a variable speed and low cost.

Diagram of Universal motor

Shaded Pole Motor

The shaded pole motor is a type of AC single phase motor. Its simply a small squirrel cage motor in which the auxiliary winding is made from a copper ring around a bit of each pole they call this the shading coil. Current in the shading coil produce a magnetic flux in a part of the pole which produces a magnetic filed. These motors have only a single winding no capacitor or switch making them reliable and economic. This type suits loads that are easily started.

Small Shaded-pole Motor

RSIR

The RSIR motor is a repulsion motor similar to the universal motor. The stator induces currents in the rotor, which create torque by repulsion instead of attraction like other motors. It has a centrifugal switch that shorts all the segments so the motor operates as an induction motor once it has met its full speed.

CSIR

CSIR means capacitor start induction run. A capacitor start is a split-phase induction motor starting with a capacitor which is series with the startup winding. The motor starts up using both windings, but as the motor comes up to speed the relay removes the start winding and capacitor from the circuit. This type is able to produce greater torque.

CSCR

 CSCR means capacitor start capacitor run. When the motor is not started both of the winding are connected to the circuit and as its comes up to speed the start capacitor is removed however the run capacitor and start winding remain in circuit. This motor runs using both windings.

PSC

The PSC or permanently split capacitor operates has no centrifugal switch.  It starts using a capacitor but the start windings are permanently connected to the power supply along the run windings. The PSC motors are mainly used when a variable speed is required like in blowers and ceiling fans.