Re: [CAD_CAM_EDM_DRO] stepper drivers

fr_murphy79 wrote:

> Hi, new member here.
>
> I just found these stepper motor drivers on ebay:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7630490137.
>
> Which links to: http://www.bright.net/~agarb/STMD/AVR_STMD.html.
>
> To me they appear to be similar to the EAS offerings, but with opto-
> isolation. Before buying, I want to see if anybody else has any
> expereince (good or bad) with them.

It uses the NatSemi driver chip
http://cache.national.com/ds/LM/LMD18245.pdf
which while more expensive than some of the offerings does have the
advantage of not needing the protection diodes or big current resistor,
so all the heat goes to the heat sink.

I've got an EAS based driver working, since the optos are on the
breakout board, and you will probably need a breakout board anyway since
the parallel port may not have enough power to drive them direct :( I
would prefer to see at least transistors on the parallel port outputs
and you will probably need buffering on the other inputs and outputs anyway.

--
Lester Caine - G8HFL
-----------------------------
L.S.Caine Electronic Services - http://home.lsces.co.uk
Model Engineers Digital Workshop -
http://home.lsces.co.uk/ModelEngineersDigitalWorkshop/
Treasurer - Firebird Foundation Inc. - http://www.firebirdsql.org/index.php