Brushless DC Motor
Your Guide on Brushless DC Motors
Isn’t it exhilarating when you discover a better method than the one you’ve been trying all along? That’s one reason to consider using brushless DC motors wherever you’re in need of a motor.
Of course, there are different motor types on the market because there’s not necessarily the best option overall. All have pros and cons. But the BLDC motor can often be the better option as it’s more efficient and in most cases more reliable than many other types.
Below you’ll find all you need to determine if it’s the motor you need.
A Brief History of the Brushless DC Motor
How it Started
While electric motors have been around since the 19th century, the early types were mostly brushed electric motors. Since that was the norm, the altered version which didn’t require brushes anymore, easily got the name of ‘brushless DC motors’.
This innovation took place quite recently thanks to the development of solid-state electronics that made it possible in the 1960s.
How Brushless Motor Works
In any electric motor, you have a challenge: The rotor turns because of the power coming from the electromagnet. However, when the rotor moves and turns the north & south poles are then in different positions. Therefore you need to change the direction of the current running through the windings of the electromagnet, each time the rotor turns 180°. When you get this right the rotor keeps on turning and the torque on the rotor stays in the same direction.
Thanks to advances in technology and specifically in semiconductor & solid-state electronics, a unique system now controls this process: It’s called an electric servo system.
In this system your motor isn’t dependent on a mechanical feature to help switch current & polarities; you have an electronic sensor that monitors the position of the rotor. As the rotor’s angle changes the sensor initiates change in transistors.
In some brushless motors, the current will change while in others it will turn off completely. When these actions happen at the exact right moments the electromagnets can continue creating torque in one direction as the rotor keeps on turning.
Why is This an Efficient Motor?
But why is this such an effective method? Why do items with these motors often get higher price tags?
Firstly the BLDC efficiency is high because you get more torque per watt. Who doesn’t want a solution where you can get more out while you have a lower input?
It’s also an efficient solution because these motors usually run much quieter than others such as the brushed motors we’ll discuss below. They can also be smaller and lighter. This makes a brushless motor a more efficient solution in unique applications: You don’t waste unnecessary space just to get a strong motor in place.
What is a Brushless DC Motor Used for?
With all these advantages you can imagine that BLDC motors have replaced traditional systems in many scenarios.
Electric Items that Use Brushless DC Motors
DC Brushless Motors in the Home
Firstly you’ll find these nifty devices all over your home these days. Because it’s easier to design smaller brushless motors than other traditional motors, it became possible to create improved versions of many home appliances such as:
- Home appliances: Your mixer, coffee machine, juice maker, and many more kitchen items probably have brushless DC motors inside.
- Smart home setups: Small, effective motors can automate various home features. That’s why Smart homes can now have electric doors, Smart door locks, fans, automatic shutters, and more. All these require motors to make the components move.
- Home care devices: The way you look after your home and yourself also becomes easier when you use motorized items. Think of the ease of modern living thanks to vacuum cleaners, air purifiers, lawnmowers, washing machines, hot water pumps and even keeping your food fresh in your refrigerator. It’s all thanks to motors.
DC Brushless Motors in Industries
If motors can enhance your own life, imagine what it can do for the world’s industries too. That’s why you’ll find them incorporated into:
- Today’s tool industry which provides more powerful tools. They don’t wear down as quickly and brushless DC motor torque is high even with lower input than some other motors.
- Cameras used in personal and professional applications have improved thanks to dynamic, small motors.
- When you enjoy exceptional coffee in a restaurant it’s thanks to motors that help grind coffee beans and power state of the art coffee machines.
- A dynamic vending machine uses a motor and won’t wear out quickly if a brushless motor is used.
- Robots are the new best thing on the market and they move thanks to specially designed motors.
- When you automate any industry the factories need motorized equipment. When motors such as the brushless motors can handle a lot of pressure and don’t wear out easily you get long-lasting equipment that can pick up & move heavy items.
It’s safe to say the technology of brushless motors can enhance almost any industry these days.
What is the Difference Between Brushed and Brushless Motors?
Perhaps when you realize how this system differs from a brushed system—the motor which started it all—you’ll see why this was such a revolutionary change. It’s also why it’s still a popular design decades later.
Above we mentioned the challenge of changing the current’s direction in any motor. Before the brushless system, an electric motor had a commutator for this purpose and this component touched unique types of contacts. These contacts were made of a substance that could conduct electricity—such as graphite—and they were called brushes.
It was the brushes’ purpose to provide current to a part of the commutator so the motor keeps on running. This was how the direction of the current was altered.
While this innovation afforded people the wonders of the electric motor for the first time in history, the brushed system had flaws:
- There was a lot of friction
- The brushes wear down
- There were voltage drops because the brushes create resistance
- The process could cause sparks
Today, these reasons prompt people to only use brushed motors in unique scenarios with low power and only where DC power (not AC) is used.
These characteristics also motivated inventors to search for better alternatives. Eventually, other types such as the brushless system were invented. Other differences between the designs include:
- Brushed systems run noisier than their counterparts
- More energy is needed to keep them running