What is stepper motor?

Stepper Motors: An Overview

Stepper motors are a type of brushless DC electric motor that divides a full rotation into a number of equal steps. Unlike regular DC motors that rotate continuously when voltage is applied, stepper motors rotate in discrete step angles. This allows for precise positioning and repeatable movement, making them suitable for a wide range of applications.

Key Characteristics:

• Precise Positioning: Stepper motors excel in applications requiring accurate angular movement. This precision stems from their step-by-step operation. See: https://www.wikiwhat.page/kavramlar/Precise%20Positioning
• Open-Loop Control: Many applications can use stepper motors without feedback sensors. The control system simply sends a specific number of pulses to achieve the desired position, assuming the motor has sufficient torque and no steps are missed.
• Holding Torque: When stopped, a stepper motor can maintain its position with a holding torque. This is useful in applications where the load needs to be held stationary.
• Low Speed Torque: Stepper motors often provide high torque at low speeds, which is advantageous in applications requiring power at slower rotations.

Types of Stepper Motors:

• Variable Reluctance (VR): These are the simplest type, relying on the principle that the rotor will move to the position of minimum reluctance (magnetic resistance).
• Permanent Magnet (PM): These use a permanent magnet rotor. They offer higher torque compared to VR motors but generally have lower step resolution.
• Hybrid Stepper Motors: These combine features of both VR and PM motors. They provide the best of both worlds – high torque and fine step resolution. See: https://www.wikiwhat.page/kavramlar/Hybrid%20Stepper%20Motors

Operating Principles:

Stepper motors are controlled by sending a sequence of pulses to the motor windings. Each pulse causes the rotor to move a specific step angle. The speed of rotation is controlled by the frequency of the pulses. The motor's position is known relative to the original position (when power was applied), this is known as https://www.wikiwhat.page/kavramlar/Incremental%20Positioning.

Applications:

Stepper motors are found in a variety of applications, including:

• 3D Printers: Controlling the precise movement of the print head and bed.
• CNC Machines: Positioning cutting tools with high accuracy.
• Robotics: Controlling the movement of robot arms and joints. See: https://www.wikiwhat.page/kavramlar/Robotics
• Camera Lenses: Controlling zoom and focus.
• Industrial Automation: Positioning components and controlling conveyor belts.

Advantages:

• Precise positioning and repeatability
• Open-loop control capability
• Holding torque
• Reliable and durable

Disadvantages:

• Lower efficiency compared to some other motor types
• Can be prone to resonance issues
• Torque decreases as speed increases
• Can lose steps if overloaded