Major Classes of Appliances

Single-Phase AC motors

The most common single-phase motor is the shaded-pole synchronous motor, which is most commonly used in devices requiring lower torque such as electric fans, microwave ovens and other small household appliances.

Another common single-phase AC motor is the induction motor, commonly used in major appliances such as washing machines and clothes dryers. These motors can generally provide greater starting torque by using a special startup winding in conjunction with a starting capacitor and a centrifugal switch. When starting, the capacitor and special winding are temporarily connected to the power source and provide starting torque. Once the motor reaches speed, the centrifugal switch disconnects the capacitor and startup winding.

Shaded-pole synchronous motor

Shaded-pole synchronous motors are a class of AC motor that uses single phase electric power to convert electric power to mechanical energy. They work by using a squirrel-cage rotor and a split stator that has copper shorting rings placed on it so as to shade a portion of the stator's magnetic field enough to provide starting torque.

The number of poles in an induction motor is an important factor in its interaction with non sine wave input. As a rule of thumb, motors with larger number of poles are more sensitive to harmonic distortion.

Incandescent Lamps

Early applications of lighting was using lamps which used a heated filament to provide light. The filament was made of tungsten and was placed inside a near vacuum glass enclosure. While it was cheap, it produced a lot of heat, so that it was inefficient too. Note that the incandescent bulb is a purely resistive load (power factor 1).

Date: 2014-12-29; view: 996