Michael Shiloh wrote:
> I could be wrong, but didn't the original poster say he his motor had 5
> leads? This would suggest an internal star connection, with 1 common lead
> and 4 leads for the other ends of each coil. If I understand this correctly,
> this would make it impossible to use in a bipolar mode.
>
> It might be possible to carefully open the case and see if the internal
> star connection can be opened, making each winding completely independent.
>
> Comments? Corrections?
>
> Michael Shiloh


Oh ho.... I could be wrong too, but even in a star connection with 5
wires, you could use it in bipolar mode, since the middle of the star
(center of both double coils tied together) would always be aprox in
Vcc/2,  Just forget the common wire, or then attach it to a VCC/2
voltage point, or to a large capacitor to ground.

Think about it.  Even sudden high current from low impedance caused by
changes in the load and torque would generate a proportional voltage
drop on both coils of the same drive.  It could create a small
unbalanced voltage due differences in the internal coils, not perfect
impedances, but it would be so close that probably could be not
considered.

I never did it, but I don't see why it would be impossible.

Wagner