Category: General Topics

Brushless DC motors offer several advantages over traditional brushed DC motors, including higher efficiency, longer lifespan, and greater reliability. However, to operate a BLDC motor, you need a specialized motor controller that provides the necessary electrical signals to control the motor’s speed, direction, and torque. Let’s explore how to select a brushless DC motor controller that will meet the needs of your application.

When it comes to choosing a brushless motor, there are a few key considerations that you should keep in mind, such as:
Speed and Torque: One of important considerations when choosing a brushless motor is its speed and torque capabilities. It is important to select a motor with enough power to complete the desired task while not overloading it.
Size: Another key factor to consider is the size of the motor, which will determine the space requirements of your application. Smaller, lighter motors are typically more efficient but may have a different torque or power output than larger motors.
Cost: As with any purchase, cost is an important factor in selecting a brushless motor. When comparing prices, consider factors such as efficiency and durability to determine which motor is suitable for your application.
Control System: Depending on the application, you may need a specific control system to operate the motor. Either analog or digital systems can control brushless motors, so make sure to select one that is compatible with your specific needs.
Environment: Consider the environment in which your motor will be operating. Different motors are designed to work in different environmental conditions, so select one that suits your application’s environment. This includes factors such as temperature, humidity, and dust levels.

Buying a BLDC motor requires a careful attention to several details. These include the parameters that describe the motor’s working characteristics, or the brushless DC motor specifications. Matching these with your project needs, you can be sure to buy a BLDC motor that suits the intended purpose or use. That’s because BLDC motors come in many different types and making the wrong choice can mean a failed project. If you have any question in choose BLDC motor, please feel free to contact us.

Following chapter is a very high overview. Please read further down about more practical info about the drive and motor types. But basics presented here is pretty universal and widely used in DIY community.

So- what we need to get these motors going? Let’s break it down to components and explain each part briefly. Commonly you need following parts to drive a stepper motor.

1. Driver
2. Microcontroller
3. Power supply

I didn’t include a power supply for (micro)controller here since it’s self-explanatory. A microcontroller like in this case Arduino- gets its power from the USB cable or battery.

Stepper Motor Driver
As we know- stepping motor can be moved one step at a time by applying electricity to coils in the correct order (and polarities). You could do this manually with some switches– step by step, but it has no practical use other than learning. This is where the driver comes into play.

The driver is doing the heavy lifting and it hides all the complexity behind a simple interface. It makes correct windings to be excited in the correct way based on the input signals. They usually have only 2 input pins which take commands in form of digital high and low. One sets the direction of rotation and other is for step commands.

Steps are given as digital pulses. After each step (HIGH) there must be (LOW) input for a moment. So drive can detect when new step command is given. If there is are no pulses given- there will be no steps done by the drive and motor.

Direction input pin can be LOW or HIGH all the time, while steps are made, depending on the direction needed. Direction does not need impulses.

Note: Some small unipolar stepper motors are driven via transistor arrays or chips like uln2003 and ln2004. There can be 4 control wires instead of 2 from the microcontroller. In that configuration, the microcontroller is directly telling which wires (coils) to energize by turning correct ones on each step “manually”. Look at example schema on the Arduino page.

Microcontroller
It’s possible to make motors move by touching the step pin on driver manually with HIGH wire. But that would not be very practical other than testing. This is why microcontroller comes into play. Microcontrollers can give many hundreds or even thousands of impulses per second so the motor can be rotated very fast and accurate.

Which has higher torque? nema 17 or nema 23？

How to choose the NEMA 23 or the NEMA 34 stepper motors?