Hi all... I'm a software guy trying to learn the ropes of electronics.
I have the goal of controlling a stepper motor using my PC parallel port to create +5v control signals. Shouldn't be that hard, right?
My understanding of 5-wire stepper motors is that there will be one common power wire, and four other wires coming out. Attach the power wire to the power source, and attach the other wires to ground (using some logic to connect the right ones to ground at the right time), and you're all set.
I bought a unipolar stepper motor... the first one listed on this page:
One thing I noticed is that the spec sheet lists that it has a "drive circuit".
Some more investigation led me here:
Since I bought a unipolar stepper, I think the first schematic on the page applies. I'm not quite sure how to read it. It appears that what I want to do is attach my parallel port data pins DIRECTLY to the bases of each of the transistors (which is what the four non-power wires coming out of the motor will be).
If that's the case, it looks like I use my parallel port control signals to activate each transistor according to activate the internal electromagnets in the proper order. Being a smart software guy, I can handle that. When I do that, the power will go through the coils, through the transistors, and into the little black boxes.
What are those little black boxes? Some sort of internal ground?
Sorry for the newbish questions, but every description of a unipolar stepper motor seems to imply that I need to build or buy my own drive circuitry. So the idea that this one might come with its own already built right in is throwing me for a loop.
If someone could confirm my suspicions, or point me in the right direction, I'd appreciate it.
Also, I don't actually have the motor in my hand yet. It's being shipped. I'm just trying to get things figured out before it gets here. :)