Views:27 Author:Site Editor Publish Time: 2016-06-05 Origin:Site
Incremental Encoders Model
This model can output pulse according to the rotary displacement of the shaft.Calculate the number of output pulse and detect rotation amount by other counter
In order to know the rotation amount of the shaft, first reset the count value of counter based on the reference position,and then add up the pulse acount which is emitted by the position by counter.
So it can select reference position randomly and detect rotation amount unlimitedly.The greatest feature is that it can add circuits,produce 2 or 4 times pulse amount of a periodic signal,improve the resolution of circuit.(Note)
In addition,it can take signal Z, which is produced when rotated a cycle , as the origin of a rotation.
Note:When high resolution is needed,generally adopt 4 frequence doubling circuit.(If carry out differential coefficient to the rising,falling waveform of phase A and B,4 times output is available and the resolution is 4 times.)
| Structure |
Rotate plate with optical pattern at the same time when rotate the shaft,the light will continue the states of permeance and shutoff corresponding to two slits.This light will change into current by the optical components correspnding to each slit,and output as two rectangular wave after waveform shaping. Another two slit should be collocated at the position that has a phase difference of 1/4 pitch with rectangular wave output.
| ◆ Output Waveform|
|Single-Rotation Absolute Model|
The data of single-rotation absolute model has the same features as that of universal absolute model.
| ◆ Output Waveform|
|Absolute Encoder Model|
This model takes rotor angle as absolute address through the code 2n parallel output.Therefore,if hold the sendout of output code bit,the sendout will increase if resolution is high,read out output code directly,detect rotating position.
Besides,when it can't read out the sign because of high-speed rotating,if reduce the speed,it will be able to read out correct data.In addition,the power is cutted off because of blackout,it is able to read out correct data after turning the power.