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circuit design of 4-wire bipolar motor COILS

Posted: Tue Apr 13, 2010 9:29 pm
by veritas
hello,
I'm taking apart a stepper motor (just like the one on the sparkfun page: Stepper Motor with cable sku: ROB-09238) and I need to know how the 8 coils of wire are connected.

The stepper motor is a 4-wire bipolar motor, but it's got 8 coils inside it. I want to cut the wires so that i can send current within each of the coils individually, but it's really hard to see which wires are coming from which (very limited viewing). (that is, I don't want to have to unravel each coil).

Does anyone know how the coils are connected up?

thank you,
veritas

Re: circuit design of 4-wire bipolar motor COILS

Posted: Wed Apr 14, 2010 1:56 am
by markaren1
I suspect that you may have coils diametrically opposite, so there would be 4 pairs in series.

Magnetically they will (probably) match up with the pole pieces.

I can't see what you are up to unless you wish to change the windings to parallel...

Please tell me a little more about the project

-Mark

Re: circuit design of 4-wire bipolar motor COILS

Posted: Wed Apr 14, 2010 9:22 am
by mac
Hi,

It's a bad idea to dismantle hybrid stepper motors.
You have a great chance to loose most of its torque due to demagnetization of the rotor.

This usually happens when rotor poles touch stator. I know because I killed one like this...

Re: circuit design of 4-wire bipolar motor COILS

Posted: Wed Apr 14, 2010 9:38 am
by veritas
yea, definitely seems true, but I don't intend to use it as a motor. :)

I just need to send current into each wire coil, and don't wanna unravel them.

The problem is i can't really see the two ends coming in and out of the coils (and it seems like there are more than 2 in some cases), so i would like a schematic of how they are actually wired up.