you might want to see if this group has some information on this
formatting link
just a thought CAE
Hi guys.
>
> I've been thinking a bit about steppers as incremental rotary sensor today.
>
> I guess its pretty simple to use them as sensors by just continuously
> normalizing the signal and sampling voltage change (looking for highs and/or lows)
> But that would only work well if the shaft moved at acceptable speed.
> I think that to slow movements would not induce any worthwhile signal. >
> So my question is.
>
> Would it not be possible to instead induce a small (small enough so the stepper
> wont try to move) current through the coil, sample the signal strength that comes
> back when the field collapses and calculate the position of the stepper between
> the "teethes". Or are there any strange irregularities in stepper coils that would
> prohibit me from effectively doing this or some other problems that might occur?
>
> Of course there would be somewhat of a problem if the stepper shaft
> was moving at the same time so I guess this kind of measurement would
> only work at standstill or when the shaft is moving very slowly (right?). >
> Anyone out there that has links to sites related to this idea or has any
> personal experience regarding this. I cant seem to find any websites
> covering this matter.
>
> regards
> /iman
>
>
> --
> So remember, kids! Every time you download a song off the Internet, you
kill a baby panda!
>