Photoelectric encoder is a kind of sensor that converts the mechanical geometric displacement on the output shaft into pulse or digital quantity through photoelectric conversion. This is the most widely used sensor. The photoelectric encoder consists of light source, optical code disk and photosensitive element. The grating disk is a circular plate with a certain diameter, and a plurality of rectangular holes are evenly opened on it.
Because the photoelectric encoder disk is coaxial with the motor, when the motor rotates, the grating disk rotates at the same speed. The detection device composed of electronic components such as light-emitting diodes detects and outputs several pulse signals, and the current motor speed can be reflected by calculating the number of pulses output by the photoelectric encoder per second. In addition, in order to judge the rotation direction, the code wheel can also provide a phase difference of 90? Two pulse signals.
Photoelectric encoder is a sensor which uses grating diffraction principle to realize displacement-digital conversion, and through photoelectric conversion, the mechanical geometric displacement on the output shaft is converted into pulse digital quantity. The common photoelectric encoder consists of grating disk, light-emitting element and photosensitive element. Grating is actually a disk with regular light transmission and light transmission.
The luminous flux received by the photosensitive element changes synchronously with the transmitted light, and the output waveform of the photosensitive element is shaped into a pulse signal, and one pulse is output every revolution. According to the change of pulse, the displacement of equipment can be measured and controlled accurately. According to the detection principle, encoders can be divided into optical, magnetic, inductive and capacitive types.
Absolute encoder:
Absolute encoder is a kind of sensor that directly outputs digital quantity. On its circular code wheel, there are several concentric code tracks along the radial direction. Each track consists of light-transmitting and light-transmitting sectors alternately. The number of sectors of adjacent code tracks is twice. The number of code tracks on the code wheel is the number of its binary digits. One side of the code wheel has a light source, and the other side has a photosensitive element corresponding to each code track.
When the code wheel is in different positions, each photosensitive element converts the corresponding level signal according to whether it emits light or not to form a binary number. The characteristic of this encoder is that it does not need a counter, and it can read the fixed digital code corresponding to the position at any position of the rotating shaft.