By the way, I have lead interesting experiments with a microcircuit from Toshiba TA8435H. On datasheet it supports 40V, 1.5A, up to 8 microsteps. I could receive stable results at 40V and 4A, having lowered frequency ШИМ up to 5kHz, but only in a is full-step mode when this frequency is still capable to support and adjust a current of phases. Urgently I recommend - the scheme is primitive, very stable also the only thing above what it is necessary to concentrate attention - above active cooling.
I tried to use it with motors from Tormach - it has appeared all the same weak...
