This week I took delivery of a 3 axis TB6560 controller board - the kind that can be found all over eBay. On examining the board and I began to think about its circuit topology.
The ground fill on the underside of the board got my interest.
That ground fill goes all the way from the GND on the DB25 to the power connector GND at the opposite edge of the board >> WHAT!!
Therefore, on this popular board despite having "opto-isolators", there is NO ELECTRICAL ISOLATION BETWEEN THE PC AND THE STEPPER POWER SUPPLY.
There are many bad things that can occur because of this.
Could someone please confirm.