An encoder is an electromechanical device that provides an electrical signal that is used for speed and position control. Encoders turn mechanical motion into an electrical signal that is used by the control system to monitor specific parameters of the application and make adjustments if necessary to maintain the machine operating as desired. The parameters monitored are determined by the type of application and can include speed, distance, RPM, position among others. Applications that utilize encoders or other sensors to control specific parameters are often referred to as closed-loop feedback or closed-loop control systems.
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1. Rotary Encoder.
2. Linear Encoder.
There are two main types: Absolute and Incremental.
The output of absolute encoders indicates the current position of the shaft, making them angle transducers.
The output of incremental encoders provides information about the motion of the shaft, which is typically further processed elsewhere into information such as speed, distance and position.
Rotary encoders are used in many applications that require precise shaft unlimited rotation, Including industrial controls, robotics, special purpose for photographic lenses, computer input device, and rotating radar platforms.
A linear encoder is a sensor, transducer or readhead paired with a scale that encodes position. The sensor reads the scale in order to convert the encoded position into an analog or digital signal, which can then be decoded into position by a digital readout or motion controller.
The encoder can be either incremental or absolute.
Motion can be determined by change in position over time. Linear encoder technologies include optical, magnetic, inductive, capacitive and eddy current.
Linear encoders are used in metrology instruments, motion systems and high precision machining tools ranging from digital calipers and coordinate measuring machines to stages, CNC Mills, manufacturing gantry tables and semiconductor steppers.