This site has "pulled" UCN5804s for $3.50 each;
http://www.alltronics.com/linear_ic_list.htm--- In
Homebrew_PCBs@yahoogroups.com, "derekhawkins"
<derekhawkins@y...> wrote:
> > In the simple controller suggested
>
> A blast from the past....Is the obsolete Allegro UCN5804 unipolar
> driver that difficult to get these days? I found 3 in my parts box
and
> 4 installed in boards here, using anything other than that for a
simple
> unipolar driver is a waste of time IMO.
>
> http://www.allegromicro.com/datafile/archive/5804.pdf
>
>
> --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
> <stefan_trethan@g...> wrote:
> > On Tue, 21 Jun 2005 05:36:54 +0200, Phil <phil1960us@y...> wrote:
> >
> > > why do most hbridges and stepper controllers use schottkys?
> >
> >
> > because they are faster. all switchmode/pwm circuits use faster
> diodes.
> > In the simple controller suggested there is no chopping, the
> frequency is
> > low, a 1n400x could be ok.
> >
> > ST