Stepper controllers

Hi,

Having just started to play with my home-brew stepper controllers on a
Pentium machine and realised that the 486 I was trying to use is just
not man enough for the job, it has occurred to me that, rather than
risking just one output card as on the 486, I am now putting my whole
motherboard at risk of destruction by feedback spikes. Even though the
motors are protected by diodes I was wondering if I should try to fit
opto isolators on the input lines to the controller cards. In looking at
published circuits, I couldn't find one which uses opto isolators
(although I did see one which seemed to use them only on the limit
switch inputs for some inexplicable reason ) so, is it usual to use
optos, is it necessary and do you know of available designs which do use
them? Thanks,

Best wishes

Ian

--

Ian W. Wright LBHI
Sheffield Branch Chairman of the British Horological Institute.
Bandmaster and Euphonium player of the Hathersage Brass Band. UK.
See our homepage at:- http://www.iw63.freeserve.co.uk or
http://www.iw63.demon.co.uk/ or
http://www.GeoCities.com/Hollywood/6067/index.html

'Music is the filling of regular time intervals with harmonious
oscillations.'