DIY servo drive? was Re: stepper vs. servo

Not laughing really. It all depends on what your goal is. If you want
to learn power circuit electronics then it is a good idea, if the
goal is having a running machine then it's probably not.

I got into electronics because I wanted a radio control for my
airplanes when I was 14. Couldn't afford the $50 so I thought "Why
not build one, how hard can it be?" I never built the control, I got
distracted by the electronics. I guess it pays to have a short
attention span.

My point is it is not simple task and it will not be cheaper. It will
be rewarding in other ways though. But for the lack of those $50 I'd
be a different person today:-)

Mariss

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

> Hello,
>
> Mariss is probably laughing right now, or at least has a "knowing"
> grin across his face...
>
> Having spent a LIFETIME in motor control, he makes it look easy. It
> isn't...
>
> There is a LOT to a servo drive... And the step-servos that Mariss
> sells have an ENORMOUS capability for the meager price requested!
> You are not likely to come ANYWHERE NEAR the performance of these
> drives with a "grab the schematic and soldering iron" approach IMO!
>
> But if you want to try:
>
> The microchip applications notes page has a design that might get

you

> started using a pic and a small pld, with a National 18201 as the
> driver...
>
> Hope this helps,
>
> Ballendo
>
> P.S. Yes, for pure DC motor control, all you need is a bridge.

(Some

> mosfets, as you say.) But getting from there to reliable, accurate
> servo operation is not a short trip... (I expect Jon E will

concur<G>)

>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Roy J. Tellason"
> <rtellason@b...> wrote:
> > On Monday 09 February 2004 11:17 pm, Albee Tang wrote:
> >
> > > By the way, instead of buying Gecko G320, can we just build one
> using some
> > > Power MOSFET construct it in H-Bridge? Wouldn't that be cheaper
> than buying
> > > a Gecko driver?
> >
> > If you know of a URL where one could find such plans, I'd sure
> like to know
> > about it...