> It's worth saying that if one has a problem as described in the OP, a four > layer board would be highly preferable.
Absolutely, but I only intend to make three such boards :) The aim is to control a rather ancient Beaver CNC mill that now belongs to a friend of mine. We scrapped the original controller for several reasons, ie it was a punched-tape unit and it had been used as a dwelling by a rather large colony of rats.... I will make the finished design available on the web, for others to use though as there seems to be a large number of these mills floating around and they are built to last a lifetime or two. The motors are rated at 7Nm, but I found that they pulled well over 9Nm reliably even when driven at just 15A (they are rated at 20A) > If you split the ground > plane up with a view to helping you achieve this, then you should > benefit, but if you just do it blindly thinkin The ground planes on both sides are now split, with a moat that separates the low-signal part from the noisy bits and they are joined at one point, the star ground. - Anders Gustafsson Engineer, CNE6, ASE Pedago, The Aaland Islands (N60 E20) www.pedago.fi phone +358 18 12060 mobile +358 40506 7099 fax +358 18 14060
