Continuing with my question, this 'hidden voltage' that Mariss mentions is what I'm concerned about in so far as it can have a damaging effect on the drive circuitry. I know that the Zylotex boards spec. a max voltage of 35v including back emf and I have to assume that all other boards are similarly constrained. So how does one allow for this? Is it sufficient to do the drill press measurement at your max. running rpm and consider the V from this to be the max. BEMF that the drive will see or do other assumptions come into play? Is the max. BEMF as determined empirically indicative of what the drive would normally see or can it be derated in some fashion because of it's AC nature?
Chris |