if you want to use ta8435, you will find schematic and pcb drawing at http://www.ottop.republika.pl/sterownik8435.shtml you only have to download it at http://www.ottop.republika.pl/download/imt901.zip need to install Eagle to use it. it's free. to make it work connect your stepper then apply at least 24V. and logic 5V. next connect ENABLE to ground to turn on the drive, and see your stepper spinning. and don't forget to use a good heatsink. I have found another link with board design where you can put a 7805 ic, and you only need acrobat reader. http://www.piter.mily.pl/index.php?i=1 http://www.piter.mily.pl/index.php?i=2 but didn't test it. it seems easy to build and is an ic used by Nanotec.
