нд, 6 жовт. 2019 о 19:56 John Dammeyer <jo...@autoartisans.com> пише:
> > Yes but does it discharge to 0V or the is there a semiconductor junction > voltage drop involved. With an external pull-down resistor, over time the > cap would discharge back through the series resistor and the pull down > resistor. Now if the device is a FET with a mill-ohm ON resistance then > it's not an issue but if it's a transistor it likely won't reach 0V. > > The only way I can make the op-amp go below 0.2V is to add a negative > supply to the op amp and bias the circuit with -0.2V so that 0% PWM brings > the output to 0V. Just didn't want to add the minus supply but I can do > that with a ICL7660. Just not sure I have one in my parts bin. > I wouldn't worry about the min voltage. IIRC every VFD has settings for voltage-rpm curve, so you can set 0rpm to 0.5V or 1V, for instance. WBR, Andrew _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
