Re: Stepper driver question (slightly O.T.)

Guys,
To explain a little further, a laminating machine has product
coming off two rolls and they go through two pressure rollers.
Sometimes the product on the bottom roll wanders to one side or the
other, and gets out of registration with the upper product. The
photocells will detect which way the product is going, and the stepper
will skew the shaft to center the product.
The stepper motor is a bipolar 440 oz.in, 4-lead, that will run on
24 or 48 volts. Since I'm "electronically deprived", I need the
controller explained in simple terms. Does anyone have a simple
schematic for a driver, or point me in the right direction. I know
that the GRex that Gecko is coming out with will do the job, but I
think it's slightly overkill for this application.
Thanks for your help.

Marv Frankel
Los Angeles


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<dave_mucha@y...> wrote:

>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Marv Frankel" <Dcdziner@p...>
> 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?
> >
> > Marv Frankel
> > Los Angeles
>
>
> It sounds like your machine has an ON/OFF setting. no signal at all
> and it is OFF.
>
> any signal and it is ON.
>
> ONE of the signals ALSO changes state of the DIR pin.
>
> Very simple to do, but the logic and electronics may not be on topic
> for the list.
>
> the motor and driver parts seem pretty close though.
>
> What size motor ? how much power do you need ? (have?)
>
> It sounds somewhat similar to Mel Bartels's telescope stuff (CNC to
> move a telescope)
>
> Alan is correct that a PIC could handle this, but so could a 555 and a
> comparitor.
>
> The comparitor would report when either input went high. and also
> report when that one went high so as to necessitate a DIR change.
>
> With the signal, the 555 would just start pulsing away.
>
> If you were running TurboCNC or some such, you could feed those
> signals into inputs and run G-Code to make the thing move.
>
> Dave
>