Re: [CAD_CAM_EDM_DRO] Stepper motor wiring-- series or parallel

In a message dated 11-Dec-00 09:15:21 Central Standard Time, salterc@...
writes:

> Which type of wiring give the best torque,, series or parallel
> I am running about 400 rpm before the motors stall out..
>
> I was just wondering if either series or parallel connections
> would make a difference..
>

Chris: I assume you have an "eight-wire", which you can parallel for two,
two-wire windings, or put in series for two pairs of two series-connected
windings, each? If you push a given current through the series connected
coils, the torque at SLOW speed would be the same as were you to feed TWICE
that current through parallel windings. But the parallel connection will
permit MUCH faster acceleration, and likely, better torque at higher
stepping-rates. The only disadvantage of the parallel is the higher current,
which requires fatter wiring (three wire-gages bigger wire between the motor
and driver), a heftier and therefore more expensive driver-circuit (which
should be of the "bipolar chopper" type for best characteristics; the older
"unipolar, tapped windings" (6-wire motors) is certainly not "state of the
art"!), and maybe more expensive to purchase.

Jan Rowland


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