To drive Unipolar Stepper Motors using MID drive

[Himanshu]

Hello friends I have purchased a RS components MID drive and I want to control a unipolar stepper motor using the same. The stepper motor is having 6 wires. I have used the same drive to run a bipolar stepper motor but I need to know as to how I can wire a unipolar motor to the same.I would like to know the connections and the disadvantages if any in driving a unipolar stepper motor using the MID drive.

[Dustin_W]

I recommend talking to RS components about the drive you are using. If the drive supports unipolar motors, the user manual should include information on how to configure the wires. The main disadvantage of unipolar steppers is that you lose about 40% of your torque as compared to bi-polar steppers. Unipolar motors are usually only good for slow moving applications.

[Himanshu]

Hello,
Thanks a lot for your comments. I am aware that I have to talk to RS people for my doubts.
I would like to use the unipolar stepper motors via the MID 7602/7604 drive. It would be nice if you could please comment on the same,

[Dustin_W]

You can drive unipolar motors with the 7602/7604, but you wire them as if they were bi-polar. The user manual (which can be downloaded from the NI web site for free) shows the way to wire the 4-phase motor as a two phase motor on page 26. The basic idea is that you either ignore the center tap - wire Phase A to Phase A, and Phase A' to Phase A', or ignore one of the phases by attaching Phase A to Phase A, and Phase A' to the center tap.

Hope this helps-