[GabeIsko]

Absolute encoders can be really good for position critical applications that you don't want to re-home all the time. Linear stages, winches - if you don't want to re home it and it needs accurate position control you start looking at an absolute encoder.

Even for speed control, hall effect sensors are kind of a poor way to track position. What is nice about hall effect sensors is that you can use them as a signal to perform brushless commutation in your motor controller, and then also use them as a poor-man's encoder. Very useful if you don't need that much accuracy in your application, but you do need brushless motors for some reason. But one of the first things I would go to as a application engineer was recommend customers get an encoder mounted.

[aidenn0]

It seems like an absolute encoder would immediately lose its advantages if a reduction gear were used though? Then you would still need to rehome the number of revolutions.

[ansgri]

Wouldn't you mount the encoder after the reductor then, where the position actually matters?

[aidenn0]

Yes, we are discussing servos packaged with an absolute encoder

[onetwentythree]

You can get multi-turn absolute encoders for these applications.

[zwieback]

Yeah, we have one application like that, a big gantry that would be a pain to home. Interestingly, the high res absolute encoder is also used to commutate the servo (it's sine) but the teaching of the commutation is a little nerve wracking. Maybe I'm getting old but the whole setup stresses me out