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Bipolar full step sequence

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Digibin:
I purchased a stepper from China on Alibaba and it came with the attached information. I don't understand the sequence table. I know what it should be, but I cannot relate this to the what's on the sheet provided. Presumably the + indicates a positive voltage, but this would mean in step 1 you would drive both ends of coil A, which can't be right.

Am I missing something or is this just poorly presented? Or perhaps is the motor construction non-standard?

Ian.M:
The document is borked.  Confirm the pinout with an ohmmeter

The following sequence will step a four wire bipolar stepper four whole steps per repeat:

--- Code: ---A1 A2  B1 B2
------------
+  -   0  0
0  0   +  -
-  +   0  0
0  0   -  + 

--- End code ---

If it goes the wrong direction either reverse the sequence, or the wires to one coil.
To half-step, activate the next coil before deactivating the previous one.

Assuming you are driving it with H-bridges, where the table says 0 0, drive both ends of the coil to the same level.




H.O:
The document doens't look righ and I'm not too sure about Ian.M sequece either.... It seems to me like it might step a standard 1.8° motor at 7.2° but I'm not sure. In my experience the full-step sequence for a bipolar motor is
--- Code: ---   A1 A2  B1 B2
   ------------
1: +  -   +  -
2: -  +   +  -
3: -  +   -  +
4: +  -   -  + 

--- End code ---

And to half-step the motor you deactivate alternating coils between steps:
--- Code: ---   A1 A2  B1 B2
   ------------
1: +  -   +  -
2: +  -   -  -
3: +  -   -  +
4: -  -   -  +
5: -  +   -  +
6: -  +   -  -
7: -  +   +  -
8: -  -   +  -
--- End code ---

Ian.M:
Yes.  I think your sequence is the preferred one.   I reproduced the one I gave from memory, and it looks like I gave the half steps without the full ones. It would still step but with much reduced torque.    I'm glad we both agree the document is bogus.

Digibin:
Yes I agree with H.O. too - for maximum torque both coils should be driven at any step. I wonder why the document is wrong... it must be a translation thing, perhaps it is interpreted differently in China.

I've tried driving the motor with this sequence via a TB6600 based board but have not had much luck. It tries to step but cannot achieve smooth rotational motion, even at very low speeds. The driver also came from China via eBay so I have reverse engineered it and am in the process of troubleshooting.

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