It’s been two days that I’m searching to understand how an incremental encoder’s precision is quadratured.
I found out that we must be counting the state changes of the two channels A and B,
where A is the signal produced by a photodiode that is lighted by a LED in a square waveform, due to the alternances of opaque and hollow parts of the rotating disque,
and B is the same signal as A but out of phase with 90 degrees, (as far as I comprehended, this shouldn’t mean that receiving photodiodes should be at an angle of 90degrees) it means that between A and B there is a quarter period of the wave spoken about earlier.
How could be this attained ? How can we separate photodiodes A and B in a such way that we have a quarter period of phase, knowing that the frequency of the rotating disque could vary and hence this phase difference between A and B will change too.
Another question, would the speed (frequency of lights) have an impact on the number of bits needed to save the elapsed distance, knowing that the distance is the same at each speed?