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Topic: Stepper Identification (Read 811 times) previous topic - next topic


Oct 03, 2013, 05:25 pm Last Edit: Oct 03, 2013, 06:15 pm by Hawk_08 Reason: 1
Hello all,

I have the following stepper, 35L048B2U from portscap, in my possesion. My motor has 6wires (would suggest universal), but on the digikey page and on the manufacturer one it tells me Unipolar. I am a bit mixed up here. I also tried to see if two wires (the common) were connected together but with no avail.

Do I have a universal or unipolar stepper?

Thank you in advance

P.S. I have added the link to the digikey page with all the datasheets.

Edit I changed the link so that it points to the exact motor


You can double check the winding resistances, but the diagram on the datasheet only shows
standard 4 and 6 wire configurations so it can be wired as a bipolar.

You probably won't want to though as it has 40 ohm windings according to the spec, so
doubled up that's 80 ohms which isn't going to let much current through!  In spirit its unipolar.

8-wire motors allow for paralleling the winding halves which really helps for bipolar drive
(since you want low-inductance), but 6-wire isn't as flexible.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]


With 6 wires it is most probably a unipolar stepper.
Measure the resistance between the contacts. According to the digikey Picture, one coil would be bn/gn/bk. The other is or/rd/yl.
You can connect gn and rd together to Vcc. The other  four wires are ABCD = or/bn/yl/bk



I just checked the Resistance of both my pairs. Bn/Blk = 126 Ohm and my Yl/Or = 186 Ohm. With ohm law (12V) i get in the worst case that I will at least have 66 mA running in my Yl/Or pair... On the spec sheet it says that the rated current per phase is 0.19 A...

Maybe I am a bit confused to has why this is bad or not.

Thank you


Both coils should have the same resistance. Like MarkT said, it should be 80 Ohm. Some cheaper multimeters have trouble with reading resistance, especially when the battery gets empty.

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