How does an encoder motor work

Another is a stepper motor. A stepper motor is a motor that rotates by a certain angle when one pulse signal is input. The stepper motor can be used without feedback open loop because the rotation angle and rotation speed are determined by the number of pulse signals applied to the motor and the interval between pulses. This method has the advantage of simplifying the system because it does not use an encoder. However, the stepper motor has the disadvantage that the efficiency is low. Because it always flows the maximum current to prevent from step-out.

By using the encoder to check whether it is rotating as instructed and feeding back the result, it is not necessary to keep the maximum current, and the power consumption of the system is reduced. In addition, by checking the load status with an encoder, the operating speed of the actuator can be maximized within the range where the motor does not step-out. This will increase the productivity. Sometimes people call the motor that is used this way the stepper servo motor. In this part, we introduced the role of encoders and where they are used.

I hope you understand the widespread use of encoders. In the next part , we will explain how the encoder works. Role of Encoder. How to measure the amount of rotation and rotating speed? What is an encoder? Where are encoders used?

An encoder is a sensor that detects rotation angle or linear displacement. Encoders are used in devices that need to operate in high speed and with high accuracy.

The method of controlling the motor rotation by detecting the motor rotation speed and rotation angle using an encoder is called feedback control closed loop method. Sensors that detect device movement and status Controllers that make judgments and process based on signals from sensors Actuators that move devices based on information processed by the controllers. How was it? See you again. The main purpose of the various types of encoders is to transform information from one format to another for standardisation, speed adjustment or safety control.

DC motors have a complex position and speed control , their behaviour is not linear and relies heavily on the load borne; this is why they need an encoder which may be embedded or not to determine and ensure a correct shaft position. There are different types of encoders depending on their design and functionality. In the post below we will analyse the main types, how they function and their main characteristics. In regard to its composition , an encoder is composed of a disc that is connected to a rotating shaft.

The disc may be manufactured out of glass or plastic, and it is coded by combining transparent and opaque areas that block the passage of light. Next, in regard to its operation , when the shaft rotates, the infrared light source emits a light that is interpreted by an optical sensor or phototransistor , which in turn generates the digital pulses depending on whether the light passes through the disc or is blocked by the opaque regions.

This results in an information sequence that allows for the control of aspects such as direction of motion, turning radius, and in certain cases, speed. Some of its most widespread applications are robotics, small household appliances or certain industrial applications that require an angular measurement.

It is the most widespread type of encoder and is composed of a light source, a rotating disc and a light detector. The disc is mounted on a rotating shaft and has opaque and transparent regions on its face.

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Company News. Privacy Policy. Terms of Use. Executive Summary Encoders convert motion to an electrical signal that can be read by some type of control device in a motion control system, such as a counter or PLC. Examples of Encoder Functions In any application, the process is the same: a count is generated by the encoder and sent to the controller, which then sends a signal to the machine to perform a function.

For example: In a cut-to-length application, an encoder with a measuring wheel tells the control device how much material has been fed, so the control device knows when to cut. In an observatory, the encoders tell actuators what position a moveable mirror is in by providing positioning feedback. On railroad-car lifting jacks, precision-motion feedback is provided by encoders, so the jacks lift in unison. In a precision servo label application system, the encoder signal is used by the PLC to control the timing and speed of bottle rotation.

In a printing application, feedback from the encoder activates a print head to create a mark at a specific location. With a large crane, encoders mounted to a motor shaft provide positioning feedback so the crane knows when to pick up or release its load. In an application where bottles or jars are being filled, feedback tells the filling machines the position of the containers.

In an elevator, encoders tell the controller when the car has reached the correct floor, in the correct position. Without encoders, you might find yourself climbing in or out of an elevator, rather than simply walking out onto a level floor. On automated assembly lines, encoders give motion feedback to robots.