Motor Encoders - Everything You Need to Know

If you're in the market for motor control systems, you've likely heard the term motor encoders. Encoders are an essential component of many motor control systems. They provide closed-loop feedback control that allows for precise control of motor speed and position. But what are motor encoders, and why are they so important? Here, you will find everything from how they work, the different types available, and why you need them for your motor control systems.

motor encoder mounted to vector motor

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What are Motor Encoders?

Motor Encoders

Motor encoders are rotary encoder measures the position and speed of a motor's shaft. They provide feedback to the motor control system, allowing it to adjust the motor's speed and position in real-time.

Types of Motor Encoders

Two motor encoder types exist: absolute encoder and incremental encoder.

Absolute Motor Encoders

Motor control systems commonly use absolute encoders for exact position information of the motor. This makes them ideal for applications that require high levels of accuracy and precision. The two main types of absolute motor encoders are single-turn and multi-turn. Single-turn absolute encoders provide a unique code for each position of the motor shaft within a single revolution. Single-turn encoders are suitable for applications where the motor shaft has limited rotation. Multi-turn absolute encoders provide a unique code for each position of the shaft within multiple revolutions. Multi-turn encoders are ideal for situations where the motor shaft rotates multiple times. Absolute encoders provide the motor control system with an absolute position value rather than a relative position value. Therefore, it can return to the exact position if a motor control system loses power or is turned off. Overall, absolute encoders are an essential component of motor control systems that require high levels of accuracy and precision. We can assist you in selecting the appropriate encoder for your specific requirements. This includes both single-turn and multi-turn absolute encoders. Contact us today to learn more about our range of rotary encoders and how they can benefit your operations.

Incremental Motor Encoders 

Incremental encoders are a common type of motor encoder used in motor control systems. They provide a signal that indicates the direction and number of steps the motor has taken. Incremental encoders are simple and cost-effective. They also provide position value; however, it is not absolute position. Motor control systems often use them for high speed and high accuracy applications, despite a drawback.

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Why You Need Motor Encoders

Motor encoders are essential for any motor control system that requires high levels of accuracy and precision. You need to know the exact position and speed of a motor's shaft to achieve the necessary control. Motor encoders are commonly used in a range of applications, including:

  • Robotics
  • Automation
  • Manufacturing
  • Medical Devices
  • Aerospace Systems and more

Whether you're looking for a motor encoder for a specific application or you're just interested in learning more about motor encoders, we're here to help. Contact us today to learn more about our range of motor encoders and how they can benefit your operations.

How to Mount an Encoder to a Motor  Encoder Mounting. Optimizing the Life and Performance of Rotary Encoders Download Now

How to Specify A Motor Encoder

When selecting components for a closed-loop control system, the motor encoder choice is first determined by the type of motor chosen in the application. The most common motor types are:

    • AC Motors Encoders AC induction motors are popular choices for general automation machine control systems as they are economical and rugged. Motor encoders are used for more precise speed control in applications using AC motors and often times need to have more robust IP, shock and vibration parameters.
    • Servo Motor Encoders Servo motors encoders (permanent magnet motor encoders) offer closed-loop feedback control systems to applications that require higher precision and accuracy and are less robust than AC induction motors. The motor encoder used on servo motors can be modular, incremental, or absolute, depending on the level of resolution and accuracy required.
    • Stepper Motor Encoders Stepper motors are cost-effective, precise, and are typically used in open-loop systems. In systems using stepper motors where speed control is required, an incremental motor encoder is often mounted allowing the stepper motor system to achieve closed-loop feedback. Stepper motor encoders can also be used in some applications to allow for improved control of stepper motors by providing precision feedback of the location of the motor shaft in relation to the step angle.
    • DC Motor Encoders DC motor encoders are used for speed control feedback in DC motors where an armature or rotor with wound wires rotates inside a magnetic field created by a stator. The DC motor encoder provides a mechanism to measure the speed of the rotor and provide closed-loop feedback to the drive for precise speed control.

Motor Encoder Mounting Options

The next factor impacting motor encoder selection is the mounting option, and the most common options are:

  • Shafted Motor Encoders: Uses a coupling method to connect the motor encoder shaft to the motor shaft. The coupling provides mechanical and electrical isolation from the motor shaft but can add cost via the coupling and the longer shaft length required to mount the motor encoder.
  • Hub/Hollow shaft Motor Encoders: Hollow shaft encoders directly mount to the motor shaft via a spring-loaded tether. This method is easy to install and requires no shaft alignment, but proper care must be taken to provide electrical isolation.
  • Bearingless Motor Encoders: Also known as ring mount, this mounting option comprises a magentic sensor assembly in the form of a ring mounted on the motor face and a magnetic wheel mounted on the motor shaft. This type of motor encoder mounting configuration is mostly found in heavy-duty applications like paper, steel, and cranes
Bearingless Motor Encoders: Also known as ring mount, this mounting option comprises a magentic sensor assembly in the form of a ring mounted on the motor face and a magnetic wheel mounted on the motor shaft. This type of motor encoder mounting configuration is mostly found in heavy-duty applications like paper, steel, and cranes.

 

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Find The Right Motor Encoder for Your Application

Use our selection tool to narrow down your search

Step 1: Select Feedback Type (Learn How to Choose)

Absolute Motor Encoders

Incremental Motor Encoders