Stepper Motor Question


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Old 01-02-09, 04:05 PM
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Exclamation Stepper Motor Question

Hi, a few days ago I hooked up a floppy drive to my computer's parallel port in order to control its stepper motor; I did this buy supplying 5v to the motor and then using the parallel port to send values to both the step terminal and the direction terminal (it was a 4 pin stepper). Intrigued, and wanting more power than the week floppy stepper, I decided to take apart my old dot-matrix printer to extract its stepper motor, the one that moves the print head. It is a pm55l-048 stepper motor (data sheet here). Unfortunately, this motor has 6 pins and I am unfamiliar with stepper motors. How can I go around wiring this to my computer's parallel port like I did with my floppy stepper?

Thanks for your help.
 
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Old 01-03-09, 01:45 PM
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Question Update to Question

Experimenting, i've found that this motor has 2 coils and I have identified the common wires by checking the resistance. I then tried putting 24v into the coils and seeing what the result is, but I am still confused as to the exact sequence of "pulses" necessary to actually turn the motor continuously. Could someone please help that is familiar with unipolar stepper control?

As for the computer interface, I found a darlington array lying around that I can use to control the 24v output using the parallel port.
 
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Old 01-03-09, 01:51 PM
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Many stepper motors have a built-in position or step completion feedback. You need the proper controller that matches the type of stepper motor involved.
 
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Old 01-03-09, 03:10 PM
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Step Motors Reference Guide

THe "center-tapped" type motor means you don't need to reverse the power polarity, therefore slightly easier to implement. These are simple motors that have no brushes, use chopped DC, and should have a long life.
 
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Old 01-03-09, 03:43 PM
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Unhappy Smoke

So I found the stepper motor sequence here and I tried to implement it with my ULN2803A darlington transistor array. Unfortunately I didn't check and the 800ma+ motor quickly burnt out the rated 500ma transistor array . What darlington transistor array should I get to be sure that I can actually power two of these stepper motors?
 
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Old 01-04-09, 05:51 PM
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I'd try the digikey catalog

Also, beware of 3 design parameters. Heat, as in how much heat sink will I need; max current; and inductive voltage spike mitigation.
 
 

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