DC & AC Electric Motors
Modern electric motors come in two distinct types, AC (Alternating Current) and DC (Direct Current) motors, the main difference between them being the way in which an electric current is passed to and from a motor. Both DC & AC models have key features which make them useful for different applications in industry, within motor vehicles and around the home.
Alternating Current Electric Motors
AC electric motors are available in 3 main types, single-phase, two-phase and three-phase, each of which is widely used today in all kinds of applications across the world.
Single Phase AC Motors
Single phase AC motors are typically used in domestic appliances such as fans, gate operators and garage door motors for the home, but also for commercial applications too. Some higher performance single phase electric motors are used for agricultural machinery, pressure washers, vacuum pumps and even refrigeration units in retail market sectors
This type of motor is able to switch between clockwise and counter-clockwise operation and can easily be mounted onto your equipment making them be able to be used for a wide array of bespoke applications.
Two-Phase AC Motors
The key advantage of two-phase motors is their ability to be able to self-start and produce torque from zero motor speed. Typically they are used for powering lifts, control systems and stepper motors however for the most part they have been made largely obsolete by the development of three-phase electric motors which produce more power from less conductor mass than two-phase.
Three-Phase AC Motors
The main reason that 3 phase motors have succeeded over two-phase is as explained above they produce higher power output, but also they produce a much smoother level of power output which makes them more ideal for more applications where continual un-interrupted power is essential. Smoother power transfer is a major step forward as single and two-phase electric motors are only able to provide power which effectively pulsates causing more vibration and over time mechanical faults in machinery and production processes.
DC Or Direct Current Electric Motors
DC motors are produced in 2 main types; with brushed and brushless and both types are used in a variety of different applications. Brushed DC electric motors have been in use in industry since 1886 whilst brushless DC motors have only been in use relatively recently since 1962 and the main differences between them are as follows:
The disadvantages of brushed DC electric motors are that they are less efficient and more susceptible to mechanical wear and tear than brushless motors and consequently are more expensive to use as they require more servicing and repair. Whilst brushless or ‘BL’ DC motors are able to produce more torque when stationary and less and less levels or torque when operated at higher speeds.
These types of Direct Current electric motors rely on what is called an ‘electronic controlled commutation’ which is in contact with a set of brushes to create and regulate the level of voltage/current to the field coils.