Re: Considering new servo product!

Regardless of the naysayers, it's time to start closing the loop
somewhere at a marketable price. Charles Hixon

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
> Hello, all,
>
> After corresponding with John Kasunich about PWM and servo
amplifiers,
> an idea ocurred to me. I can make a modification to my existing
Universal
> Stepper Controller board (entirely by changing the configuration
PROM)
> that will make it put out PWM and direction instead of step and
direction.
> I could make a very simple servo amp that takes in PWM signals,
and doesn't
> have much smarts other than current limit and fault trip. This
should be
> pretty cheap to make. If I can do enough with the PID parameters
in
> EMC to get good response and stability, this should make a VERY
simple
> and cheap closed-loop servo system. And, if I can do DC brush
motors,
> I could then expand it to permanent magnet brushless motors (often
> called DC brushless) too. That would cost 2 more power
transistors,
> one more half-bridge driver, and a few CMOS chips.
>
> This DOES give up some smoothness at the very low speed end, and
could
> run into trouble if there is a lot of spring in a thin leadscrew
or some
> other
> mechanical pole in the response. But, it should work as well as a
Gecko
> 320, since that is what they are doing in hardware. Plus, all the
> parameters
> will be accessible from software. It also makes it possible to go
to higher
> voltages and currents than the Gecko can handle.
>
> This would also allow me to offer a complete package all from one
source,
> and to offer kits (all the complete and tested boards, no box or
power
> supply)
> as well as complete NC driver boxes.
>
> Any comments?
>
> Jon