Problem- Phase balance a encoder

[bherr]

Talked with Heidenhain today after installing another ERO 115-125 encoder that I got from keith here on the forum. Found out that you need to have a phase meter to align the light emitting diode with the wheel, etc. Anyone ever done this and what is a phase meter?

Ben

[Al_The_Man]

Fancy name for a double beam 'scope!
Many years since I did this, it used to be the norm on early Ferranti-Packard scales that had incandescent light source.
The method we used involved inputting one channel output (A) into the scope X input and the other (B) into the Y and produce a Lissajous figure to produce and indicate the exact 90deg difference.
http://www.jmargolin.com/mtest/LJfigs.htm
In the link shown, you need the full circle.
If no one here has the procedure for your encoder, I suggest you contact Heidenhain, they should have it.

[gus]

never heard of such a thing

[bherr]

Originally Posted by Al_The_Man Fancy name for a double beam 'scope! Many years since I did this, it used to be the norm on early Ferranti-Packard scales that had incandescent light source. The method we used involved inputting one channel output (A) into the scope X input and the other (B) into the Y and produce a Lissajous figure to produce and indicate the exact 90deg difference. http://www.jmargolin.com/mtest/LJfigs.htm In the link shown, you need the full circle. If no one here has the procedure for your encoder, I suggest you contact Heidenhain, they should have it.

Al,
I got a dual trace scope, so I guess I'll need to contact rick at Heidenhain. thanks for the heads up. You defiantly are the Man!

Ben

[Al_The_Man]

Fortunately current quadrature encoders do not require this procedure, in the field, anyway.
Al.