Quad Encoder Testing

[Tim Ganz]

OT: What is the proer way to connect a quadrature encoder to a oscilloscope for testing.

This is a 2 trace scope. We are not using the z channel of the encoder.

Would it be a+ / a- on one trace and b+ / b- to the second trace. Would the a- and b- go to the ground clip of the probe of each trace?

 

[Tim Ganz]

What range of scope is best for this? In mHZ?

 

[BryanG]

Yes to everything you said. The range totally depends on how fast you are turning the encoder and so is impossible to answer.

Bryan

 

[Tim Ganz]

We are running the motor the encoder is reading at 1750 rpm ( full Speed) How would i calculate the proper scope range?

 

[steveb1475]

How many pulses/revolution from the encoder? How many pulses do you want to see on the scope?

 

[Tim Ganz]

Encoder is 1024 PPR. I don't know how many pul;ses we may want to see on the scope. What would be a good number for troubleshooting? How many would you need to see on the screen to get a consistant reading?

Sorry if my questions are so out there. I was a maintenance mechanic for many years but my company shutdown so the job i have now you have to do electrical and i am struggling to learn it all.

 

[OkiePC]

1024pulses x 1750rpm = 1792000pulses/minute / 60 = 29866.67 pulses/second, or a pulse width of ~1/30000 second. If you set up each division to be 1/100,000 second, the pulses will be about 3 divisions wide.

I normally make sure I set up the voltage correct, and then start turning the knobs until the picture looks good, then I look at the settings to see what I did.

 

[Tim Ganz]

Thank You All.

 

[rdrast]

I purchased one of these last year, and it has more then paid for itself. Much simpler then bothering with a scope.