Re: [CAD_CAM_EDM_DRO] Stepper driver question (slightly O.T.)

Marv Frankel wrote:

>Guys,
> I have an industrial application that requires only one stepper
>motor, and two photocells. When one photocell goes dark, the stepper
>motor cranks clockwise. When the other photocell goes dark, the
>stepper motor cranks counterclockwise. I'm looking for a fairly simple
>driver. Any suggestions?
>
>

You mentioned that you'd be using a 440oz-in stepper for this. If you
don't need all the power you might consider using an SLA7062M driver
chip. This is a microstepping chopper type driver that takes step and
direction inputs. You can get them for about $12 each:
<http://www.techkits.com/#sla7062>

That site also as a carrier board you can use with it for about $70. It
would be a pretty simple solution for driving the motor.

For generating the appropriate control signals you could use pure logic
as suggested in other posts, but I'd suggest using a microcontroller, a
PIC or AVR, and a BASIC or C compiler.

The main problem with this is that getting set up with development tools
can be pricy. If you don't intend to do other projects it would be more
cost effective to either have someone else write the program to your
specs or use logic, which doesn't required programming. The logic
required is pretty simple, so if you have any experience with that it
might be easier to impliment.

The advantage of a microcontroller is that you can much more easily
adjust the response of the system to the inputs so that you can tweak it
to do exactly what you want.

Dave K