4-wire (Bi-Polar) Stepper Motor for EM36

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RickS
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4-wire (Bi-Polar) Stepper Motor for EM36

Post by RickS » Tue Dec 04, 2012 1:46 pm

The EM36 will have trouble in controlling a 4 wire, Bi-Polar Stepper Motor, the EM36 being designed for a 5/6 wire Uni-Polar version.
As the Bi-Polar (4 wire) Stepper Motor coils lack the centre taps of the Uni-Polar (5/6 wire), the Bi-Polar Motor requires a different way of being controlled. It needs to be able to reverse the current flow through the coils by alternating polarity of the terminals.
The Bi-Polar Stepper Motor has 2 coils and although these coils are identical, they are not electrically connected.
To be able to reverse the polarity of the voltage across either coil, and to be able to energize these coils in sequence, you will need a device/circuit called an H-Bridge. This will allow the current to be reversed through the coil by closing the appropriate software switches.

If you are competent enough with electrical components and a soldering iron to make one yourself, great, otherwise you can get in touch with OMEX at:-

http://www.omextechnology.co.uk

They have a suitable device (OMEM6030) and although it doesn't appear on their website, it's worth giving them a call if you're going to go down this route.
Follow this link for a better and fuller explanation of why you would need this:-

http://en.wikipedia.org/wiki/Stepper_motor

Regards,
RickS

See thread http://www.gems.co.uk/gemsforum/viewtopic.php?f=5&t=479 for an example of how to set a 4-wire system up.

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