Unipolar stepper motor control

[frogdogbb]

Hey all I am trying to sort through data for controlling a unipolar stepper motor with a microcontroller. I have done this before but the hardware was already in place on a development board. What I need is a way to drive a 12V Unipolar stepper with a microcontroller. I have found a number of chips that may do what I need as far as switching and back EMF protection but not voltage conversion. I looked at a L6220 it says it can handle up to 50V on the output but the data sheet makes no mention of how this is accomplished. Maybe there is an easier way or maybe I am missing a part of the puzzle. Anyone have stepper motor experience?
Thanks
Ben

 

[light_bulb]

look like it does no voltage conversion, you need an external source, the center tap on the diodes stops emf. i'd use 4 mosfet here with built in diodes straight to the microcontroller and an add on power suppy, probably would be cheaper too.

 

[ravenprp]

Hi Ben,

Controlling a unipolar stepper motor with a microcontroller can definitely be a bit tricky, but it sounds like you have a good start by researching chips that can handle switching and back EMF protection. In terms of voltage conversion, you may want to consider using a step-down voltage regulator to bring the 12V down to a more manageable level for the microcontroller. Another option could be using a transistor or MOSFET to switch the higher voltage on and off for the motor.

As for the L6220 chip, it's possible that it uses a built-in voltage regulator to handle the higher output voltage. However, without more information from the datasheet, it's difficult to say for sure. I would recommend reaching out to the manufacturer or consulting with other engineers who have experience with this chip to get a better understanding of how it handles the output voltage.

In terms of other options, you may also want to look into using a dedicated stepper motor driver chip, such as the DRV8825 or the A4988. These chips are designed specifically for controlling stepper motors and may have built-in voltage conversion capabilities.

I hope this helps and best of luck with your project!