Encoder

Encoders convert mechanical movement into electrical signals.  This conversion is carried out optically, magnetically or mechanically. Encoders are subdivided into rotary and linear depending on the movement involved. Rotary encoders are used in the field of tool spindles to measure the rotational speed.
Encoders work with very small (incremental), counting or absolute material measures as line patterns, magnetisation or contacts.
Absolute encoders directly assign a position to each measured value. No reference value is required and it is also possible to drive directly to a particular position after the machine has been at a standstill.
Incremental encoders require a reference value from which all positions can be determined.   If the machine is started anew, the reference value must first be determined before correct position values can be reported.
Rotary encoders are also known as rotary position transducers.  With the help of a precision measurement wheel, these output a sine and cosine voltage which are converted into the relevant output signals by the electronics. The exact determination of the position of the rotor is essential for the regulation of the speed. Furthermore, this also enables the exact positioning of the tool, for example a thread cutter.