Re: Stepper motors as encoders

Hi,

There was an article about using steppers as encoders in one of
the "popular electronics" (they've changed names/ownership so much in
the last few years I can't keep up) magazines within the last few
years.

I believe you can get more than 100ppr if you "count" all the
transitions... I think schmitt triggers were involved in the circuit
in the article.

Hope this helps.

Ballendo

--- In CAD_CAM_EDM_DRO@y..., grant.fair@s... wrote:
> I am thinking of playing with stepper motors as shaft encoders. Has
> anyone had any luck with this approach?
>
> In practical terms, 100 pulses per revolution is the best
resolution
> which would be available. The main virtue of this approach would be
> low cost, since .9 degree/steppers (which give only 100 ppr) seems
to
> be the smallest step size widely available from surplus sources,
where
> they are available in the $2 range. The electronics to interface a
> stepper so it outputs 5V pulses is cheap - 2 comparators, and a few
> R's, C's and diodes, plus a 5V power supply.
>
> Any comments? Would 100 ppr have any value with DRO's? Of course
> greater resolution could be achieved mechanically.
>
> Grant