Re: Stepper motor 101 was Re: Are steppers considered low frequency motors?

I think you should avoid it. Way too much loss in the transistors and
the idea to use linear ramps misses much of the theory. A stepper used
as an synchronous AC servo needs a sin/cos signal or it won't have
smooth torque through the steps.

On 8/9/06, Alan Marconett <KM6VV@...> wrote:
> Hi,
>
> So what about Linistepper?
>
> http://techref.massmind.org/techref/io/stepper/linistep/index.htm
>
> Appears to be an attempt to do a linear ramp (triangle?) to drive a stepper?
>
> Alright, it's got a PIC on it (I like that), but I see two BIG resistors,
> for a unipolar driver.
>
> If we really want a sine wave, why don't we just use a linear amp and drive
> it with a sine wave? Class A (B? even C?...) Wastes too much power I'll
> bet.
>
> Alan KM6VV
>
> > ballendo:
> > In half-stepping we do a little better job of approximating the sine
> > wave, because we turn one OR two coils on at a time. This puts
> > a "step" in the simulated sine wave, so it looks a little more like a
> > complete sine wave. (Very little actually in appearance; but quite a
> > bit better in performance)
> >
> > Microstepping is simply adding more and more "levels" of definition
> > to the simulated sine waves that all stepper drivers use to create
> > discrete steps of movement from these motors. And as the simulated
> > sine wave gets better; so does motor performance at slow speeds.
> >
>
>
>
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