1. Home
  2. Knowhow

The characteristics of stepper motors, brushed motors, and brushless motors are summarized

Date:2023-11-16   Author:XINDA MOTOR
When designing equipment that uses motors, of course you need to choose the motor that is best suited for the job required. We have previously introduced the characteristics and driving methods of brush motors, stepper motors and brushless motors. Here we will compare their characteristics, performance and characteristics, hoping to be your reference when choosing a motor. However, since motors in the same category include multiple specifications, please use them only as a reference. In the end, you still need to confirm the detailed information through the technical specifications of each motor.

Characteristics of small motors

The characteristics of stepper motors, brushed motors, and brushless motors are summarized in the table below.

  stepper motor brushed motor Brushless Motor
rotation method Through the drive circuit, the armature winding is excited in the order determined by the phases (there are two phases, three phases, and five phases). The armature current is switched by a sliding contact rectifying mechanism of brushes and commutator. Brushless by replacing the functions of brushes and commutators with magnetic pole position sensors and semiconductor switches
Drive circuit need unnecessary need
Torque The torque is relatively large. (especially torque at low speed) The starting torque is large, and the torque is proportional to the armature current (the torque at medium to high speed is relatively large)
spinning speed Proportional to the input pulse frequency. There is a out-of-step area in the low speed range Proportional to the armature applied voltage. Speed decreases as load torque increases
high speed rotation Difficulty spinning at high speed (need to slow down) Due to the limitations of the brush and commutator rectification mechanism, it can reach up to several thousand rpm. It can reach up to several thousand to tens of thousands of rpm.
Rotation life Determined by bearing life. tens of thousands of hours Limited by brush and commutator wear, several hundred to several thousand hours Tens of thousands to hundreds of thousands of hours are determined by the bearing life.
Forward and reverse methods Need to change the sequence of excitation phases of the drive circuit Reverse the polarity of the pin voltage to reverse the Need to change the sequence of excitation phases of the drive circuit
Controlling Open-loop control is possible in which the rotation speed and position (rotation amount) are determined by command pulses (but there is a problem of out-of-step) Constant speed rotation requires speed control (feedback control using speed sensor) Torque control is easy since torque is proportional to current
Ease of acquisition Easy: There are many varieties Easy: Many manufacturers and varieties, many options. Difficulties: Mainly specialized motors for specific applications
price If the drive circuit is included, the price is more expensive than the brushless motor Relatively cheap, coreless motors are a bit pricey due to their magnet upgrades If the driver circuit is included, the price is more expensive

Performance comparison of small motors

A radar chart lists performance comparisons of various small motors.

Speed-torque characteristics of small motors

The following summarizes the speed-torque characteristics of each small motor. It can be considered that brushless motors and brushed motors are basically the same.

Key takeaways

Attachment: Types and classifications of motors