Hopefully I am not bring an old subject from the dead, but searches lead to broken links.

For steppers, what are the conventions?

I see the following:







Then there is also the A /A B /B convention....

1. What does the dot represent (on the last drawing)? On some diagrams, they only give you one dot for vertically drawn coil.

2. From all the diagrams, we can conclude that A = A = A1 = Black (for that particular stepper), /A = C = A2 = Red, etc. How on earth did that convention come about (A to C, B to D)?

 

Hi Gibson, I'm not really sure there is any convention. My general impression was that such diagrams are just illustrative to show the winding configuration in this case, there are 2 separate windings and what colour / pins the wires are to them. As opposed to something like this:
http://www.mosaic-industries.com/em...cts/stepper-motors/stepper-motor-windings.png

I suppose technically you would make the assumption as you say:A = A = A1 = Black (for that particular stepper), /A = C = A2 = Red
But I am not sure how well it actually holds, normally for me at least, if the motor buzzes rather than moves, then I need to swap over the wires on one winding!

For the last diagram, the "dots" are often used in transformers and indicates the same direction of wrapping of the wire on the winding.

 

There are also two versions, the Bi-polar and the Uni-polar, the former is usually the higher torque version.

Max.

 

Thanks! I guessed convention was not likely.

Also, dumb question, does the direction of the winding really matter?

 

Winding direction = rotary direction, depending on polarity of applied power..
Max.

 

Thanks! I guessed convention was not likely.

Also, dumb question, does the direction of the winding really matter?

From my (very limited) experience, as a user you do not have access to verify any direction of winding. Just the terminals to measure resistance.

 

From my (very limited) experience, as a user you do not have access to verify any direction of winding. Just the terminals to measure resistance.

And winding "direction" wouldn't mean anything if it could be determined. Since motor rotation is controlled by the way power is put into the winding, not the direction they are wound.