RE: [CAD_CAM_EDM_DRO] Quadrature?

~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.

Thanks Jan,

Now that's how I can understand it. You and I need to go bowling. Of all
of the literature and replies that I've run into in the last day, that made
the most sence of an explaination for quadrature. I'm not knocking the
others explainations. Moreso, I'm knocking my ablity to understand the
other's splaination.

Now, more questions. If an encoder, say a rotary encoder, has a count per
revolution of 2500, and I have a pitch on a screw that is say 10 tpi. Then
its possible to have a dro with .00001"? (one hundred thousanth of an inch)
Or does the initial count of the encoder mixed with th pitch of the screw
make the difference? Or does the screw have anything to do with it at all.

I are confusered.

Scot



~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!
~
~~