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I am using a microcontroller to control a bipolar stepper motor. Do you think this circuit will work? Answered

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I am going to use a Basic Stamp microcontroller to control 3 bipolar stepper motors. Tell me if you think this circuit will work. (all stepping signals will be handled with the microcontroller) This is just a modified h-bridge.

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lemonie (author)2009-07-18

Correction: two ways, but this still isn't a good circuit

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galaxyman7 (author)lemonie2009-07-18

Why isn't it a good circuit?

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lemonie (author)galaxyman72009-07-18

It doesn't look quite right, but in trying to find something better, I'd say this search result is pretty good for you?
http://www.google.co.uk/search?hl=en&q=stepper+motor+controller&meta=&cts=&aq=2&oq=stepper+motor

L

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galaxyman7 (author)lemonie2009-07-18

The reason why those are so much more complicated is because the hardware handles the signal outputs. They use clock IC's and other components to go from a simple "on, off" input to a pulsing output. I am replacing all of those components with a microcontroller. It will generate the signals to drive the motor. Since I only need 1 motor running at a time, multitasking is not needed.

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lemonie (author)galaxyman72009-07-18

I was under the impression that steppers needed pulsed feeds, but I'm open to the possibility of being mistaken there. Does the circuit represent just one motor? There's a better way to flip polarities, but I still can't remember the right word for it - and I was hoping someone else would.... L

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galaxyman7 (author)lemonie2009-07-18

Yes, a bipolar stepper has 4 wires and two sets of coils. I'm just not sure of the sequence of turning the coils on and off.

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steveastrouk (author)galaxyman72009-07-19

Have you read "Jones" on Stepping Motors - it seems to be the internet's standard reference. I'd certainly use a driver chip for the high current bits , even if you sequence the stepper yourself.

Jones:

http://www.cs.uiowa.edu/~jones/step/

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galaxyman7 (author)lemonie2009-07-18

I just modified my circuit so that they can be reversed and turned off seperately. Here it is. I think I might switch one of the coils so that they are the same direction. That would allow for half stepping. Here's an article on how to control steppers. http://wolfstone.halloweenhost.com/Motors/stpint_StepperMotorIntro.html
One coil can be positive or negative, while the other is off, or both can be on with the same polarity.

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lemonie (author)galaxyman72009-07-19

A lot of transistors, but I still can't remember what it's called that I was thinking of. Still I'm sure you'll get it to work. L

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lemonie (author)2009-07-18

I only see one way of energising the coils (image), only one transistor needed really. You want to re think this. How do you want to run the motors / what type of switching functions do you need? L

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