On Sunday 18 October 2020 14:23:29 Thaddeus Waldner wrote: > > 1. direction changes are slow. No consequences when driven by the > > human hand running a joystick on the side of the seat, but important > > for computer control. > > Typical delay for changing direction is 600microseconds. This is less > than the typical LinuxCNC servo period of 1ms. The reason for this > delay is probably due to the relatively slow switching speeds of the > high-side mosfets, to eliminate shoot-through. If you plan to change > motor directions no faster than the LinuxCNC servo thread, why is this > too slow? > > This is too slow to drive the motor in "synchronous antiphase” or > with a triangular waveform but I don’t get why you want to do that. > But there are many things I don’t get. :) > > > 2. No evidence from the waveforms shown that the pwm is used for > > anything but a logic clock. At no point in the waveforms shown > > starting on page 13, is there any evidence of the pwm actually > > modulating the outA or outB voltage in time with the input pwm. This > > is designed as an on/off control only, and low standby current > > consumption in the very low microamps was the prime specification > > driver. The boards I have ordered, unless they are doing something > > that STM does not know or show, are not capable of pwm driven analog > > control. > > As per the timing diagrams, the PWM input directly controls the > low-side power mosfet with a 1.5 to 5 microsecond rise/fall time. > On what page do you see that, Thaddeus?
Thanks. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
