Re: [CAD_CAM_EDM_DRO] stepper driver hookup

mr.c@... wrote:

> I went out to the shop last week to try out a Vexta 2 phase stepper
> driver that I just bought. I have two other Vexta drivers and motors
> in 5 phase and am pleased with them. Well, here is my dilemma. This
> driver,unlike the others does not have pulse and direction inputs. It
> has instead a clockwise input and a counterclockwise input. Is there
> any way to hook this unit up as step/direction input? Or am I stuck
> using this to drive a rotary head that will only turn one direction?

Unless there is an option jumper inside the driver (which is quite
possible),
then you have to change the signals. What you need is two and gates
(assuming
the pulse polarity is the same). A 74LS08 will do. Assuming positive
pulses,
and positive=clockwise, what you do is hook the step signal to one input
of
both gates, and the direction signal to the other input of the gate that
produces
the clockwise signal. For the counterclockwise gate, you need to invert
the
direction input. So, you need to add an inverter, too, like a 74LS04.

If this is not clear (hard to do this in text) or the signal polarities
are
different, I can give you the correct circuits. All of this assumes
there
is some setup delay after direction changes before the step pulse.

Jon