Re: Quadrature?

Jan,

If you think about it, a step motor in the full step mode is a
quadrature "decoder". You send it a quadrature sequence and
it "decodes" it into CW or CCW motion. Funny how things work.

Mariss

--- In CAD_CAM_EDM_DRO@y..., JanRwl@A... wrote:
> In a message dated 22-Mar-02 02:50:45 Central Standard Time,
> scotr@b... writes:
>
>
> > Quadrature. So, what is it? And how should I approach it
when starting
> > to set up a dro?
>
> Scott: Surely someone much wiser than I will answer this
more "properly",
> but here's THIS ignernt old troll's answer to your
question: "Quadrature"
> means when two "square-wave" signals are 90° out of phase with one-
another.
> That is, the second channel (wave-form) CHANGES only when the OTHER
channel
> (wave-form) is stable.
>
> These two signals (channels, wave-forms) are usually named "A"
and "B". If
> "B" makes a transition from LO to HI when "A" is LO, then the
(UP/DOWN-)
> counter counts 1 "UP". If "B" should make a transition from LO to
HI when
> "A" is HI, then the (UP/DOWN-) counter will count 1 "DOWN". This
way, the
> "electronics" can tell whether the encoder producing "A" and "B" is
moving CW
> or CCW.
>
> It'd be much easier to explain "face-to-face" with a sketch-pad and
pencil,
> but I am sadly too ignernt to do it here.
>
> If you have similar straight-forward questions about such simple
stuff, feel
> free to e-mail me direct.
>
> Jan Rowland
>
> P.S: This technology had me addicted, years ago, and I delved into
it until
> I learned a little about it, and THEN I discovered STEPPER MOTORS,
and how
> SIMPLE they made things. As I had (nor now have!) ambition to get
into the
> wonders of servos and encoder magic, I stuck with simple steppers
in building
> my own home-brew CNC toys, and I have never regretted it!
>
>
> [Non-text portions of this message have been removed]