Homebrew_PCBs

Using a microcontroller to replace several discrete hardware
components is where it's at but unfortunately that doesn't seem to be
the case here. The Allegro UCN5804 and several other single chip
unipolar drivers from the mid nineties (now obsolete) not only did
that but also had built in high current drivers. Furthermore, IIRC,
you cannot get any reasonable torque from this approach unless a
voltage at least 5 times the rated voltage of the stepper is used in
conjunction with current limiting ballast resistors. These resistors
get very hot and have to be heat sinked. This is outdated technology
and to mimic it using a microcontroller seems nothing more than an
academic exercise in programming.


--- In Homebrew_PCBs@yahoogroups.com, Robert Hedan
<robert.hedan@v...> wrote:

> Has this been brought to the attention of the group yet?
> http://www.dakeng.com/u2.html
>
> It's a PIC 16F84 along with the Assembler code to convert standard

TTL step

> and direction signals to the phase signals used by a unipolar

stepper motor

> for two axes.
>
> Robert
> :)
>
>
>
>
>
> Be sure to visit the group home and check for new Links, Files, and

Photos:

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