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# stepper motor with 6 wire

Posts: 35
edited July 2004
parallax has·code for·stepper motor (12V)with 5 wires.·However I have a stepper motor (5V)with 6 wires and I don't know how to program it. Does anyone knows how to program a stepper motor with 6 wires ?

• Posts: 65
edited July 2004
I'm pretty sure 2 of the wires are commons, and can be tied together to work with the 5-wire setup.

Correct me if I'm wrong on this.

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"OIOOIOOO OIIOOIOI OIIOIIOO OIIOIIOO OIIOIIII OOIOOOOO OIIIOIII OIIOIIII OIIIOOIO OIIOIIOO OIIOOIOO OOIOOOOI"
• Posts: 23
edited July 2004
Correct. if you think of the stepper motor as having 4 coils, you can have 8 total wires. If you take two of those coils and tie them together as commons then you still have 4 coils, but only 6 wires. This is the UNI-polar arrangement.

You can also use only one coil on a side with an H-Bridge driver. And that will work with a 4 wire motor, a 6 wire motor and an 8 wire motor. This is BI-Polar.

The H-bridge reverses polarity on the coil so the common could be a dead short in a 5 wire motor.

The benifit of an 8 wire arrangement is that you can parallel two coils and wind up with a 4 wire motor. There is a very slight mechanical advantage of the parallel arrangement, something on the order of 3% gain.

Also, for a single coil motor, you would use full nameplate amps, and if you used a 6 wire or 8 wire with the centers in common to create a 4 wire motor with the two coils in series, then you would drive that with only half the amps. It offers the same low speed power at half the energy input. But is does not offer the same high speed performance.

Be careful to isolate the connon taps so they do not touch anything.

Dave
• Posts: 81
edited July 2004
Yea, most likely they are 2 commons and should be the same color. Is there any markings on the motor? If so you may be able to find a data sheet. If not you'll have to break out the ohm meter to find the pin out.

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"The more you do, the more you know"
• Posts: 34
edited July 2004
If your motor is not marked and you can't find documentation on it, it is possible to determine which wire is which with a series of tests.· The book "Easy Step'n" by David Benson describes the technique.· The book is also a good introduction to stepper motors explaining how to drive them in various modes (full step, half step, unipolar, bipolar, etc.).

http://www.sq-1.com/estoc.html
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• Posts: 35
edited July 2004
I am not sure which wires are common. I attach a diagram of the motor with this reply. color of wires are indicated
• Posts: 65
edited July 2004
The red and green are your commons, as they are the "center tap" of the coils.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"OIOOIOOO OIIOOIOI OIIOIIOO OIIOIIOO OIIOIIII OOIOOOOO OIIIOIII OIIOIIII OIIIOOIO OIIOIIOO OIIOOIOO OOIOOOOI"
http://68.11.58.106:69/ircchat2/jicra-1.2.2/index-js.html

• Posts: 35
edited July 2004
following code is for 12V stepper motor on parallax.com

' P4 -> ULN2003.1, ULN2003.16 -> Phase 1 (Black)
' P5 -> ULN2003.2, ULN2003.15 -> Phase 2 (Orange)
' P6 -> ULN2003.3, ULN2003.14 -> Phase 3 (Brown)
' P7 -> ULN2003.4, ULN2003.13 -> Phase 4 (Yellow)

How do I know which phase is which wire for my 5V stepper motor?
• Posts: 65
edited July 2004
It appears the color coding matches up, if however it doesn't behave properly, you could check out http://www.cs.uiowa.edu/~jones/step/·for some information that will help you determine which wires are which.

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"OIOOIOOO OIIOOIOI OIIOIIOO OIIOIIOO OIIOIIII OOIOOOOO OIIIOIII OIIOIIII OIIIOOIO OIIOIIOO OIIOOIOO OOIOOOOI"
http://68.11.58.106:69/ircchat2/jicra-1.2.2/index-js.html

• Posts: 23
edited July 2004
To check the phases, all you need is an ohm meter that can show low ohms, less than 10 typically.

Connect any wire to one lead and then test all the other wires.

The center tap will be the exact same to all other wires. Since that is the common, that should be simple.

From that point, you can select all the other 4 wires and pretend they are correct and connect them to your driver board.

If you do have them correct, the motor will spin normally and in the proper direction. If you only have the direction reversed, then all you need to do is to swap either of one side of the motor connectors.

If the motot just vibrates, then you have two phases out of alignment and need to swap one wire from one set of phases to the other.

If you want to add a short protection, use a lightbulb in front of your power supply. if you do pull a short, the bulb will light and indicate a short. if there is no short, then the bulb will act as a low ohm resistor.

Dave
• Posts: 34
edited July 2004
Actually, since he has a 6 wire motor each of the commons will show continuity to two and only two other wires. Moreover, the common will exhibit the same resistance to each of the remaining two leads for which it is a common while measuring across the non-common pair will exhibit double the resistance value. That's how you identify the common lead out of three which indicate continuity.
• Posts: 135
edited July 2004
The best resource on the Web for steppers: http://www.cs.uiowa.edu/~jones/step/.

Regards,

Al Williams
AWC
Easy RS232 Prototypes: http://www.awce.com/rs1.htm
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• Posts: 35
edited July 2004

Thanks! everybody. It works.