RE: Stepper questions

HI Dave,

That's an interesting point! I don't recall reading anything like that, I
could be wrong. Basically the windings do not interact as far as I know.
Actually, one would think that "turning around" a winding, as in a bipolar
drive would take longer. The field would have to collapse before it could
build up in the opposite direction. Therefore wouldn't a unipolar drive,
with its four windings have the advantage? And I'd think that the unipolar
stepper would have the further advantage of having two windings available
for microstepping. Half-stepping of a unipolar stepper is relatively easy!
Just alternate one winding on and two windings on! Ever see a 5 phase
stepper? I still haven't figured out the stepping sequence for that, but
they do 400 steps!

I'd like to see the "dual" specs for such a stepper. I'm guessing that they
rely on a difference in current, and possibly some dissipation differences
between the two modes. Same current * turns = same torque!

I have the opinion that it's better to use ALL of the windings available.
But maybe it doesn't matter.

Alan KM6VV

> > A bipolar drive will provide more torque to a given motor than
> > unipolar. This is why we see the "same" size 23 double stack 3amp, 1
> > ohm motor nowadays labeled with either 280 oz.in. (bipolar) or 200
> > oz.in. (unipolar).
> >
> >
> I was under the assumption that on a uni-polar, one coil with a
> decaying charge prevents the other coil from attaining the same power
> as fast as a bi-polar drive ?
>
> Dave
>