Rotary encoders

[Wp100]

Hi,

Was just about to order an incremental rotary encoder from Farnells , not a device I have used before, but on checking the encoders datasheets seems there are two distinct types, though the difference not detailed in the general description ?

One types has Outputs as "Two phase A &B"
The other type as "Output of A and B signals, proportionate to phase difference"

Have looked around but not seen any other mention of the phase difference type ?

Just going on these descriptions would think the "Two phase A &B" is the right type to use for typical pic/arduino diy projects where just "rotarty encoder" is specified ?

thanks

 

[JimB]

There has been a recent bit of discussion about encoders here:
https://www.electro-tech-online.com/threads/those-damned-encoders.140913/#post-1178658

Two phase A and B sounds about right, can you give a link or a Farnell part number so I can have a look at it?

JimB

 

[dr pepper]

I've only ever come accross quadrature ones, I think what you mention are the same thing.
One diffo I have come accross is that some give an a pulse, then a mechanical click then the b pulse, and others give a and b before the click and some a and b after the click.
Some sofware I wrote hung itself up if the encoder was inbetween a and b pulses.

 

[BobW]

Yes, these should be quadrature encoders.
I just had a look at the Farnell site to see what they offer in encoders. I checked a couple of datasheets for ALPS encoders, and must admit that they were rather confusing. The datasheets I looked at made no mention of quadrature outputs. So I have no idea what they are supposed to be.
I've used the inexpensive Panasonic EVE line of mechanical encoders, debounced with a simple RC network, and have had good results with them. These are certainly good enough for experimentation, though I might pick a better one for the final version of a project.

 

[Wp100]

There has been a recent bit of discussion about encoders here:
https://www.electro-tech-online.com/threads/those-damned-encoders.140913/#post-1178658

Two phase A and B sounds about right, can you give a link or a Farnell part number so I can have a look at it?

JimB

Hi

Ah, missed that post.

Was just looking for an encoder to complete this project , so thought a simple lo cost incremental type would do.
https://www.ad7c.com/projects/ad9850-dds-vfo/

The parts I was looking at are on page 2617 of the current online catalogue the APLS EC12 range though the same seems to apply to their EC11 range.

Was looking at parts 206-5074 and 206-5076, their respective datasheet here, though nowhere in the catalogue is there any mention of the different (?) types of output, only when you look at the manufacturers datasheet

**broken link removed**
**broken link removed**

At the price not bothered about ordering one of each, its more knowing what are the right parameters.

 

[camerart]

Hi

Ah, missed that post.

Was just looking for an encoder to complete this project , so thought a simple lo cost incremental type would do.
https://www.ad7c.com/projects/ad9850-dds-vfo/

The parts I was looking at are on page 2617 of the current online catalogue the APLS EC12 range though the same seems to apply to their EC11 range.

Was looking at parts 206-5074 and 206-5076, their respective datasheet here, though nowhere in the catalogue is there any mention of the different (?) types of output, only when you look at the manufacturers datasheet

**broken link removed**
**broken link removed**

At the price not bothered about ordering one of each, its more knowing what are the right parameters.

Hi WP100,

I used quadrature encoder a few years ago. From the two inputs A and B the system can see which way the disc is turning and by counting the speed also.

I used HCTL2000 chips for the decoding.

What happens is sequence: Ahigh Bhigh Alow Blow Ahigh Bhigh=forward Ahigh Bhigh Blow Alow Bhigh Ahigh= Reverse.

Cheers, Camerart.