The Three Main Types of DC Electric Motor

Did you know that there are three main types of DC electric motor to choose from, each suited to very different purposes? Read on to find out what they are.

Brushed A brushed DC electric motor contains a split ring commutator, which is used to convert AC current (the electricity that is sent to our houses) to the DC current the motor needs to run. Brushes run around the commutator ring, displacing the electricity where it needs to. Some people believe that, as a brushed motor requires brushes to run, it is prevented from operating at its maximum level. The brushes create friction, as well as physically scratching the surface of the commutator. Eventually, both the brushes and the ring will need to be replaced. The brushes are able to create so much damage as they are made of strong heavy duty materials. It was originally copper (that practice is now obsolete) and now carbon is used because it lasts longer, creates less friction, and is actually cheaper than copper. The installation of a brushed motor is also much cheaper than many other DC types.

Brushless A brushless DC electric motor also contains a commutator that is used to convert our regular AC current to DC. Unlike the brushed DC model, the brushless electric motor has its commutator on the outside. As it’s designer found a way to completely eliminate the use of brushes, the motor is said to have a longer life span that its brushed counterpart. As well as this, a brushless electric motor is able to run for longer without maintenance, has an increased power output and is much more efficient. Because of this, the brushless DC electric model is very well suited to heavy duty work. This electric model runs much cooler than the brushed DC motor and the various AC motors, furthering its increased life and making it a more popular choice.

Stepper The least common of the DC electric motors, the stepper, is also a brushless-type model that relies solely on electromagnets to rotate the internal shaft. It has an iron tooth cog that is connected to the internal shaft, and around this shaft are located four toothed electromagnets at different intervals. When the electric motor has been switched on, one of these toothed magnets will attract the centre cog until their teeth are aligned. Then the first magnet will switch off as the second turns on, rotating the cog towards it until their teeth are also aligned. The process continues for the remaining two magnets until the centre cog has completed a full rotation. Stepper DC electric motors are found in many daily applications, such as in CD drives, printers, scanners, some children’s toys, and even in satellites. Due to their brushless functioning, stepper electric motors are also known to be long lasting.