Modern Electric Motors

Over the years, modern electric motors, also known as brushed motors have increased in popularity. Today, you will find them in a lot of electronic devices, such as cordless power tools, that are used in a variety of home and industrial applications. It seems that many manufacturers of electronic devices are jumping on the brushless motor bandwagon. So what is a brushed motor, and what advantages does it offer?

What is a Brushless Motor?

To understand what a brushless motor is, we have to take a brief look at what they evolved from, which is brushed motors.

Basically, a brushed motor contains carbon brushes that transfer current coming from a power source (battery or power outlet) to commutator contacts located on the motor’s shaft. Now, the shaft contains a spinning armature/rotor inside of it and two permanently installed magnets on the outside. When the electric current reaches the armature, the electromagnet inside of it generates a magnetic field that repels the magnets, causing the motor to spin.

A brushless motor removes the carbon brushes and the commutator contacts from this setup. At this point, you might be asking yourself how power even reaches the armature when there are no brushes and commutator contacts to facilitate the transfer of current. Well, that is where some sort of circuit board is used to control the power that is supplied to the armature. The power is controlled using sensors located on the circuit board. For this setup to work, the armature is moved to the outside of the shaft while the magnets are placed on the inside.

What are the Advantages of Brushless Motors?

The removal of the brushes and commutator contacts coupled with the addition of a circuit board is where the advantages of the brushless motor lie.

Brushless Motors are More Efficient

As the motor spins, so do the commutator contacts, and the brushes come in constant contact with them as they spin. This leads to a number of undesirable outcomes. For one, it means that the brushes will eventually wear out. Secondly, this produces a lot of electrical noise and sparks. Thirdly, the sparks cause some energy to dissipate.

Since there are no brushes in brushless mortars, they are much more efficient. For one, there is no wearing of brushes to worry about, meaning brushless motors last longer. Secondly, the noise and sparks are significantly reduced. Thirdly, fewer sparks mean less energy dissipation, meaning brushless mortars require less power than their brushed counterparts to spin.

Brushless Motors are “Smarter”

The circuitry in the brushless motors that control the current makes brushless motors “smart.” Regardless of what you are doing, brushed motors will transfer the same amount of current to the motor all the time (unless there is some switch that you can use to manually control this). Brushless motors, on the other hand, have circuitry that can detect how much current the motor needs depending on the task you are doing at the moment.

Perhaps an example will best illustrate how this is a huge advantage. Suppose you are in the process of drilling some wood. Depending on how thick the wood is, a brushless motor will detect how much current should be transferred to the motor based on how much resistance the drill is facing. This has the advantage of making work more efficient. If the drill is cordless, less battery power will be used for the job compared to a brushed motor, which will use the same battery power no matter the job.

Now that you know the advantages of brushed motors, you can see that their popularity is well deserved. They are a drastic improvement over their brushed counterparts and that is what makes them a better alternative to brushed mortars. That is why many companies are using them in their electronics and many consumers are buying them.