A recently purchase Omron rotary encoder has 5 leads 5V, 0V , A+, B+, Z+. my driver wants to see A-, B-,Z-. I put 2K resistors from 5V and 0V to each *- pin but no joy. what am I missing to get this to work. Yes I could buy an 8 lead encoder, but I want to learn from my mistakes if I can.

 

hi Tom,
Are you saying your driver wants 0V to negative voltage going signals.?
E

 

If the driver expects to also see the complementary signals, What you need is a differential convertor IC I have the type I use somewhere. I will post it ASAP.
Here: 26LS31.
Usually indicated by A, /A , B, /B, & Z /Z.
Max.

 

A recently purchase Omron rotary encoder has 5 leads 5V, 0V , A+, B+, Z+. my driver wants to see A-, B-,Z-. I put 2K resistors from 5V and 0V to each *- pin but no joy. what am I missing to get this to work. Yes I could buy an 8 lead encoder, but I want to learn from my mistakes if I can.

Which encoder did you buy / can you post the data sheet or a link to the data sheet, please?

 

Which encoder did you buy / can you post the data sheet or a link to the data sheet, please?

Omron encoders come in single ended or differential, It sounds as though the OP bought a single ended version, but needs a differential.
The single ended come in open collector to 5v to 24v, the differential 5v.
http://www.ia.omron.com/products/family/491/specification.html
It is easy to convert using the 26LS31. IF 5v version.
Max.

 

Omron encoders come in single ended or differential, It sounds as though the OP bought a single ended version, but needs a differential.
The single ended come in open collector to 5v to 24v, the differential 5v.
http://www.ia.omron.com/products/family/491/specification.html
It is easy to convert using the 26LS31. IF 5v version.
Max.

My take on it is that he needs the single-ended complements to A+, B+, and Z+, but that he has a unit with positive-true open-collector outputs which he's hooked up as shown on the left, below.
Notice that the output can't rise past Vcc/2, which means it may never trigger the quadrature detector.
Shown on the right is a simple common-emitter inverter which will output A\ and provide a fairly low impedance voltage output from nearly Vcc to nearly GND.

Note also that the sim is done by switching the input to the IRLED in the encoder instead of interrupting the light beam via the codewheel.

 

Although he is talking about the option of buying a 8 lead encoder instead to solve his problem which is the complementary style which is the same thing as hanging a 26LS31 on the output of his present one.
Hopefully we will hear back from the OP?
Max.

 

You need this. https://cnc4pc.com/differential-line-driver.html
I have just used it last week for this exact purpose you describe. it works fine

 

Although he is talking about the option of buying a 8 lead encoder instead to solve his problem which is the complementary style which is the same thing as hanging a 26LS31 on the output of his present one.
Hopefully we will hear back from the OP?
Max.

I just checked. The module I linked to is indeed using the 26LS31. Getting it already on a breakout board with pull up resistors and misc supporting components and headers for $9 I think is a pretty good deal.

You need this. https://cnc4pc.com/differential-line-driver.html
I have just used it last week for this exact purpose you describe. it works fine

 

Weird they did not include terminals for the Z /Z , solder connection only.
But overall makes it an easy fix.
I think I would have preferred terminals on both ends though.
Max.

 

Weird they did not include terminals for the Z /Z , solder connection only.
But overall makes it an easy fix.
I think I would have preferred terminals on both ends though.
Max.

Me too. I'm not thrilled about the RJ45 interface; not sure why they did it that way, but it works. I did not need the Z so I did not notice it was missing. They have another version that includes the Z and is actually $2 cheaper
https://cnc4pc.com/c72-differential-line-driver.html

 

I usually use Belden 9891 Ethernet Transceiver cable for encoders, so I need a little different means of termination over the RJ45.
Max.

 

Thanks to all, I will order a conversion board and get it working. I have built a digital controlled Dividing Head, but had a stall/slip issue with a open loop stepper. So I will add the encoder to the dividing spindle, and use it to control the divisions.

Tom

 

Thanks to all, I will order a conversion board and get it working. I have built a digital controlled Dividing Head, but had a stall/slip issue with a open loop stepper. So I will add the encoder to the dividing spindle, and use it to control the divisions.

Tom

Cool. If you order one of the ones I linked to, make sure it's the 2nd one. The 1st one doesn't have the Z pulse