Encoder is a kind of sensor, which is mainly used to detect the speed, position, angle, distance or counting of mechanical movement. In addition to industrial machinery, many motor-controlled servo motors and BLDC servo motors need encoders to be equipped for motor controller to detect commutation, speed and position, so it has a wide range of applications. According to the detection principle, the encoder can be divided into optical type, magnetic type, inductive type and capacitive type. According to its calibration method and signal output form, it can be divided into incremental encoder and absolute encoder. Photoelectric encoder is based on grating diffraction principle to realize displacement-digital conversion. It has been used in machine tools and computer instruments since 1950s. Because of its simple structure, high measurement accuracy and long life, it has been valued and promoted at home and abroad, and has been widely used in precision positioning, speed, length, acceleration and vibration.

 

Contact Encoder - The output of a brush is used. A brush contacts the conductive area or the insulating area to indicate whether the state of the code is "1" or "0".

 

Contactless Encoder - The acceptance sensor is a photosensitive element or a magnetic element. When using the photosensitive element, the state of the code is expressed as "1" or "0" in the light transmittance and non-light transmittance regions.

 

Incremental encoder - The displacement is converted into periodic electric signal, which is then converted into counting pulse, and the number of pulses is used to indicate the displacement. When the rotating axis rotates, there are corresponding pulse outputs, whose counting starting point is arbitrarily set, which can realize infinite accumulation and measurement of multiple cycles.

 

Absolute encoder, a sensor that directly outputs digital quantities, is often used in motor positioning or speed measurement systems. Because each angle position corresponds to a unique digital encoding, its indication is only related to the starting and ending position of the measurement, but not to the intermediate process of the measurement.

 

Rotary Incremental Encoder - Pulse output when rotating, counting device to know its location, when the encoder does not move or power failure, relying on the internal memory of counting device to remember the location.

 

Multi-circle absolute encoder - Applying the principle of clock gear machinery, when the center code disc rotates, it drives another group of code discs (or more groups of gears, multi-groups of code discs) through gears, and adds the encoding of cycles on the basis of single-circle encoding, so as to expand the measurement range of the encoder, determine the encoding by the mechanical position, and the encoding of each position is unique without repetition, without memory.