Electronic multiturn encoders how they work ?

i am intersted in understanding how multiturn encoders without mechanical gears work ?

i have 2 theories from what i read : 1- internal battery (with eeprom to count) ?!
2- internal micro generator (energy harvesting tech)

but i am reading in this website : https://www.kuebler.com/k2014/j/en/...bsolut_Multiturn/Welle/optisch/Standard/F5863

" Patented Intelligent Scan Technology™ with all
singleturn and multiturn functions on one single
OptoASIC - offering the highest reliability, a
high resolution up to 41 bits and 100 %
magnetic field insensitivity. "

Click to expand...

but no clarification on how this work , does any body have an idea ??

if the post need moving somewhere else please advise

It says it is powered from 5V at ~50mA on the data sheet. I'm not sure why you thnk it has an internal power source.
It probably has a standard quadrature optical encoder inside it with the sin/cos output option coming from a look up table in the ASIC.

Brian.

this is a absolute multi-turn encoder , so I understand that there is an absolute disk capable of giving the position within one turn . but how it is able to count the number of turns if it is powered off and moved, tradianlly this is solved by using internal gears and multiple absolute optical disks . but here they say it is a patented new technology where they implement this on an ASIC . but they donot specify how ?

There are two questions you arose regarding to this Encoder. One refers to how the pulses are marked. It can be easily answered if you think on the inner wheel as a HDD disk, having several digital bits magnetically recorded on it surface. The other question refers to the fact that this Encoder has a logic inside, "encoding" the real position. Once the specifications mention a 41 bits resolution, probably it is built as an absolute encoder.

Hi,

although it is a multiturn encoder it is not said, that the multiturn information is valid after power loss.
Maybe it is only valid as long as the encoder is powered.

I try to get more informations...

Klaus

Very likely Klaus.

An ordinary conventional incremental encoder coupled up to a simple up down counter could potentially produce non volatile absolute position, if it were internally battery backed.

KlausST said:

Hi,

although it is a multiturn encoder it is not said, that the multiturn information is valid after power loss.
Maybe it is only valid as long as the encoder is powered.

I try to get more informations...
Klaus

Click to expand...

thank u
this is the most logical answer till now , althogh i thought when an encoder is marked as absolute whether single or multiturn , it means you must now where the position even if the power is off , for example in a elevator or lift , the advantage of multiturn absolute encoder vs incremental is that if power is lost you still now where the lift is without having to go "HOME" or do an initialize .
waiting your more info

regards

Many things like electronic callipers and digital position readouts on machinery use incremental encoders with up down counters.
These give an absolute readout starting from zero, either at initial power up, or after you push a "zero the reading" button.

So basically the zero position reading datum point can be set anywhere in the travel.

None of these are true absolute position encoders, the up down counter needs to be manually initially set to some reference point every time the equipment is powered up.

Warpspeed said:

Many things like electronic callipers and digital position readouts on machinery use incremental encoders with up down counters.
These give an absolute readout starting from zero, either at initial power up, or after you push a "zero the reading" button.

So basically the zero position reading datum point can be set anywhere in the travel.

None of these are true absolute position encoders, the up down counter needs to be manually initially set to some reference point every time the equipment is powered up.

Click to expand...

i donot know if this is meant to answer my question , but it is unrelated to the point, i understand incremental encoder quiet well , the encoder i am asking about is being marketed as REAL absolute encoder ( from a very respectful manufacturer ). other wise there is no point of using it and paying almost triple the price of an incremental encoder. the up down counter can be easily implemented on a micro or PLD or similar ICs .
and if you read what i have quote from the website especially this sentence : " with all singleturn and multiturn functions on one single OptoASIC "
they might be using an EEPROM to save the number of rotations , this might explain the ability to retrieve position in case of power off , but if the encoder is rotated during power off , the position well be lost !!

by the way the mechanical multiturn absolute encoders i have tested donot suffer any of these issues , if this encoder is supposed to be a "NEWER" replacement product , it should have the same performance.

thanks for the effort mate , i wish somebody who have used such product could give a decisive answer :bang::bang::bang:

The most likely conclusion is absolute position over one turn, multi-turn position isn't preserved after power loss.

But the datasheet isn't clear in this regard, why not asking the manufacturer or your local distributor?