Re: [CAD_CAM_EDM_DRO] Re: rotary hand encoder wheels with detent

Hi Ballendo, Doug, list,

Yes, I saw some distorted sine waves from a NEMA #23 stepper last
night. I had suspected that the outputs would be in quadrature, and
that an op-amp comparitor of some sort would be required to get
reasonable square waves, from which step and direction could be
derived. I wasn't planning on a converter.

The stepper DOES give a nice feel! Kinda big, 'tho.

Alan KM6VV


ballendo wrote:

>
> Alan,
>
> No converter is needed! The stepper will output quadrature when it is
> turned. (okay, 90 degree out of phase sine waves, but scmitt triggers
> fixes that<G>). The issue is the varying voltage at which the quad
> signals are produced; you need "boost" when turned slowly, and "clip"
> when turned fast. One of the pop tronics type mags had a circuit for
> this awhile back.
>
> Hope this helps.
>
> Ballendo
>
> --- In CAD_CAM_EDM_DRO@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi Doug,
> >
> > Yeah, I gotta agree, The stepper gives it a nice feel (but ya can't
> spin
> > it)! I must have been imagining (wishful thinking) that my encoder
> had
> > some feel.
> >
> > Do I recall the last time we talked about using steppers for
> encoders,
> > that there was a circuit for a "pulse generator" or "quadrature
> > generator" for a stepper? I haven't sat down to see if I can
> figure one
> > out, but it seems that a few opamp comp's, and perhaps a few F/F's
> > should be able to generate quadrature signals. Anybody wanna give
> it a
> > try?
> >
> > I'm USING my brand new dual shaft steppers!
> >
> > Alan KM6VV