unipolar vs bipolar stepper

Mariah Brown

written by

Mariah Brown

update on

unipolar vs bipolar stepper


Welcome to this comprehensive guide on unipolar vs bipolar stepper motors. Are you looking to understand the differences between these two types of stepper motors? Maybe you’re wondering which one would be better suited for your specific project needs? Well, you’re in the right place. In this article, we will break down the key characteristics, pros, and cons of both unipolar and bipolar stepper motors so that you can make an informed decision. As someone who has already gained experience around unipolar vs bipolar stepper, you’re likely aware that choosing the right stepper motor is crucial for the success of your project. So, let’s dive in and explore this topic further!

Unipolar Stepper Motors


Unipolar stepper motors are widely used in various applications due to their simplicity and cost-effectiveness. These motors have two windings per phase, with a center tap in each winding. This design simplifies the motor controller circuitry, making it easier to drive the motor with standard integrated circuits.


Unipolar stepper motors are energized using a sequence of pulses that alternate between the different coil phases. By energizing the coils in a specific order and sequence, the motor rotates step by step. This process is facilitated by a unipolar motor driver, which switches the current flow through the motor winding.

Due to their design, unipolar stepper motors have more torque at low speeds. This makes them ideal for applications that require low-speed precision, such as CNC machines, 3D printers, and robotic arms.

Bipolar Stepper Motors


Bipolar stepper motors consist of two separate windings per phase. Unlike unipolar motors, bipolar motors do not have a center tap in each winding. This design complexity requires specialized motor drivers to control the current flow in the windings.


Driving bipolar stepper motors involves more intricate circuitry as you need to reverse the current flow in the windings to change the motor’s rotational direction. This requires an H-bridge configuration, which can be implemented using specialized stepper motor driver ICs or discrete transistor circuits.

Compared to unipolar motors, bipolar stepper motors offer higher torque output. Additionally, these motors provide more control over the motor’s speed, acceleration, and positioning. They are commonly used in applications such as robotics, industrial automation, and high-precision equipment.

Comparison Table

Aspect Unipolar Stepper Motors Bipolar Stepper Motors
Complexity Low High
Cost Affordable Relatively Expensive
Torque Higher at Low Speeds Higher Overall
Control Less Precise More Precise
Applications CNC Machines, 3D Printers, Robotic Arms Robotics, Industrial Automation, High-Precision Equipment

Frequently Asked Questions (FAQ)

Q: Which stepper motor type is easier to drive, unipolar or bipolar?

A: Unipolar stepper motors are generally easier to drive because their control circuitry is simpler compared to bipolar stepper motors.

Q: Can I convert a unipolar stepper motor to bipolar?

A: No, it is not possible to convert a unipolar stepper motor to a bipolar configuration. The internal winding design and connections are fundamentally different.

Q: Are unipolar stepper motors more energy-efficient than bipolar stepper motors?

A: No, unipolar and bipolar stepper motors have similar energy efficiency. However, unipolar motors may draw more current due to their winding configuration.

Q: Which stepper motor type is more suitable for applications requiring precise control?

A: Bipolar stepper motors are better suited for applications requiring precise control, thanks to their ability to change direction and control current flow in the windings.

Q: Are unipolar stepper motors louder compared to bipolar stepper motors?

A: Yes, unipolar stepper motors tend to be louder due to the alternating current flow in the windings, which produces more vibrations and noise.

Q: Can I achieve higher speeds with a unipolar or bipolar stepper motor?

A: Bipolar stepper motors are generally capable of achieving higher speeds due to their higher torque output and precise control over the motor’s movement.

Q: Are unipolar stepper motors more commonly used in hobbyist projects?

A: Yes, unipolar stepper motors are often preferred in hobbyist projects due to their simplicity, availability, and lower cost.

Q: Can I use the same motor driver for both unipolar and bipolar stepper motors?

A: No, unipolar and bipolar stepper motors require different motor driver configurations due to their distinct electrical characteristics.

Q: Which type of stepper motor is the most versatile for various applications?

A: While both unipolar and bipolar stepper motors have their advantages, bipolar motors are generally considered more versatile due to their broader range of applications and precise control capabilities.

Q: What are the disadvantages of using a unipolar stepper motor?

A: Unipolar stepper motors have lower torque at higher speeds, reduced precision compared to bipolar motors, and tend to dissipate more heat due to their increased current draw.


Now that you have a thorough understanding of the differences between unipolar and bipolar stepper motors, you can make an informed choice for your specific project needs. Unipolar motors are a great choice for low-speed precision applications, while bipolar motors offer higher torque and overall control capabilities for more demanding projects. Whichever type you choose, always ensure you have the appropriate motor driver and controller to maximize the motor’s performance.

If you’re interested in learning more about stepper motors, motor controllers, or other related topics, feel free to explore our other articles on the subject. Happy motorizing!


Leave a Comment