Homebrew PCBs

>You should forget these and get some 5V 1A or so motors, but for 
>other reasons rather than this.

That's exactly what I found in one of my storage boxes in the garage 
over the weekend. Found three 5V 1A unipolar steppers that were 
hooked up to a board with three UCN5804 drivers. The power supply was 
30V and there were 25 ohm high wattage resistors in series with the 
coils.  A poor man's substitute for chopper drives. Built this around 
5 years ago. I'll probably dump these on E-bay someday.

--- In Homebrew_PCBs@yahoogroups.com, Alan King <alan@n...> wrote:
> Robert Hedan wrote:
> 
> > Uh, change in plans.  I've been fiddling around with the 24V 
motors I have
> > on hand and they appear to be VERY demagnetized.  I didn't notice 
this until
> > I picked up a set of smaller steppers and noticed a drastic 
difference in
> > resistance.
> > 
> 
> 
>    LOL..  If by 'resistance' you mean cogging, that has nothing to 
do with being 
> demagnetized.  Short all the wires on one of your motors together, 
and see if it 
> isn't pretty damn hard to turn.
> 
>    You should forget these and get some 5V 1A or so motors, but for 
other 
> reasons rather than this.
> 
> 
> > So now I have to get myself decent steppers.  I'm not going back 
to the
> > local surplus store, I'll just get the same problem (dozens of 
steppers all
> > piled in the same box).  I'm going to buy larger motors for the 
CNC machine
> > later, but for now, I'm looking for decent intermediate motors 
that will
> > make my drilling station work as well as machine wood and 
plastics.
> > 
> 
>    They're usually in a can, and even if they weren't just tossing 
them in a box 
> isn't likely to demagnetize much of anything.  They're shipped in 
boxes of 50 or 
> 100, about as close as just tossed together.
> 
> 
> > I was checking these pulls from Xylotex:
> > http://www.xylotex.com/DoubleStepper.htm
> > 
> > Problem is now I have to reconsider a totally new driver 
circuit 'cause
> > these are bipolar steppers.  Can I modify my schematic without 
TOO much
> > trouble?  Or am I better using a new design?
> > 
> 
>    Probably better to find some good solid 5V unipolar motors and 
get using them 
> until you've learned a bit more about steppers in general.  Some of 
it simply 
> comes from getting and using all types, start simple.
> 
> Alan