Alan B. Pearce wrote:
>
> >One thing I think might have been touched upon is that for various reasons,
> >maybe your particular encoder simply can't handle going beyond a certain
> >speed.

> It is most likely the rise and fall times of the phototransistor itself that
> sets the maximum speed. These are very sensitive to the way the transistor
> or diode is biased, and to the type of transistor or diode used.


And many optical encoders are very fast but have
caps added in the opto circuit to act as low pass
filters, to limit HF noise etc. You should be able
to see these caps and replace them with smaller
caps to increase the speed.
-Roman

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