1. According to different ways of working classification
(1) Incremental: It is a pulse signal (also has positive and negative cosine signals, which are then subdivided and chopped out with higher frequency pulses) at each unit of rotation, usually Phase A, Phase B , The phase-Z output, phase A and phase-B are pulse outputs delayed by a quarter of a cycle from each other, and the positive and negative transitions can be distinguished according to the delay relationship, and by taking the rising and falling edges of phase A and phase B, ; Z phase is a single lap pulse, that is issued a pulse per lap.
(2) Absolute value type: It corresponds to a circle, and each reference point emits a unique binary value corresponding to the angle. Recording and measuring can be performed in a plurality of positions by the external marking device.
2. Read by different ways into: contact and non-contact.
3. According to the signal output type is divided into: voltage output, open collector output, push-pull complementary output and long-term drive output.
4. Encoder mechanical installation form classification
(1) Shaft type: Shaft type can be divided into clamping flange type, synchronous flange type and servo mounting type.
(2) sleeve type: sleeve type can be divided into semi-empty type, all-air type and large diameter and so on.
5. Encoder working principle can be divided into: photoelectric, magnetic and contact brush type.
What is the role of the encoder?
Encoder Encoder is a type of sensor used to detect the speed, position, angle, distance or count of mechanical motion. In addition to industrial machinery, many motor-controlled servo motors, BLDC servo motors Need to be equipped with encoder for motor controller as commutation, speed and position detection so the application of a wide range. According to the detection principle, the encoder can be divided into optical, magnetic, inductive and capacitive. According to its scale method and signal output form, divided into incremental encoder and absolute encoder. Optical encoder is the use of grating diffraction principle to achieve displacement – digital conversion, from the 50’s began to be applied to machine tools and computing instruments, because of its simple structure, high measurement accuracy, long life and other advantages, at home and abroad have received the attention and promotion, precision Positioning, speed, length, acceleration, vibration and so has been widely used.
Contact encoder —- using brush output, a brush contact conductive area or insulation area to indicate the status code is “1” or “0”.
Non-contact encoder —- Accepted sensors are light-sensitive components or magnetic sensors, the use of light-sensitive components to light-transmissive area and opaque area to indicate the code state is “1” or “0”.
Incremental encoder – the displacement is converted into periodic electrical signals, then the electrical signal into a count pulse, with the number of pulses that the size of the displacement. In the rotation of the shaft, there is a corresponding pulse output, the counting start arbitrary set, enabling unlimited multi-turn summation and measurement.
Absolute encoder —- Direct output of digital sensors, commonly used in motor positioning or speed system. Because each angular position corresponds to a unique digital code, its indication is only related to the start and end positions of the measurement, regardless of the intermediate process of the measurement.
Rotary Incremental Encoder —- to output pulse while rotating, know the position through the counting device, relying on the internal memory of the counting device to remember the position when the encoder does not move or power failure.
Multi-turn absolute encoder —- The principle of using clock gear mechanical, when the center code wheel rotation, through the gear drive another set of code wheel (or sets of gears, sets of code wheel), based on single-turn coding Increase the number of laps on the code to expand the measurement range of the encoder to determine the coding by the mechanical position, each unique position code is not repeated without memory.